Title Page

UM-22417-AK

DT9837 Series
User’s ManualCopyright Page

Trademark and Copyright Information
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information about Measurement Computing trademarks.
Other product and company names mentioned herein are trademarks or trade names of theirrespective companies.
© 2019 Measurement Computing Corporation. All rights reserved. No part of this publication
may be reproduced, stored in a retrieval system, or transmitted, in any form by any means,electronic, mechanical, by photocopying, recording, or otherwise without the prior written
permission of Measurement Computing Corporation.

NoticeMeasurement Computing Corporation does not authorize any Measurement Computing
Corporation product for use in life support systems and/or devices without prior written consent
from Measurement Computing Corporation. Life support devices/systems are devices or systems
that, a) are intended for surgical implantation into the body, or b) support or sustain life and whose
failure to perform can be reasonably expected to result in injury. Measurement Computing
Corporation products are not designed with the components required, and are not subject to thetesting required to ensure a level of reliability suitable for the treatment and diagnosis of people.

FCC
Page

Radio and Television InterferenceThis equipment has been tested and found to comply with CISPR EN55022 Class A andEN61000-6-1 requirements and also with the limits for a Class A digital device, pursuant toPart 15 of the FCC Rules. These limits are designed to provide reasonable protection against
harmful interference when the equipment is operated in a commercial environment. Thisequipment generates, uses, and can radiate radio frequency energy and, if not installed andused in accordance with the instruction manual, may cause harmful interference to radio
communications. Operation of this equipment in a residential area is likely to cause harmfulinterference, in which case the user will be required to correct the interference at his own
expense.
Changes or modifications to this equipment not expressly approved by Data Translation could
void your authority to operate the equipment under Part 15 of the FCC Rules.

Note: This product was verified to meet FCC requirements under test conditions that
included use of shielded cables and connectors between system components. It is importantthat you use shielded cables and connectors to reduce the possibility of causing interference
to radio, television, and other electronic devices.

Canadian Department of Communications Statement
This digital apparatus does not exceed the Class A limits for radio noise emissions fromdigital apparatus set out in the Radio Interference Regulations of the Canadian Department ofCommunications.
Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites
applicables aux appareils numériques de la class A prescrites dans le Règlement sur lebrouillage radioélectrique édicté par le Ministère des Communications du Canada.

Table of Contents

Table of Contents
About this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Intended Audience. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
How this Manual is Organized . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Conventions Used in this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Related Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Where To Get Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Chapter 1: Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Hardware Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Key Features of the DT9837 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Key Features of the DT9837A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Key Features of the DT9837B. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Key Features of the DT9837C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Supported Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Windows Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Linux or macOS Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Supported Accessories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Getting Started Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Part 1: Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Chapter 2: Setting Up and Installing the Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
System Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Attaching Modules to the Computer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Connecting Directly to the USB Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Connecting to an Expansion Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Configuring the DT9837 Series Device Drivers (Windows Only). . . . . . . . . . . . . . . . . . . . . 36
Chapter 3: Wiring Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Preparing to Wire Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Wiring Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Wiring Signals to the Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Connecting Analog Input Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Connecting an Analog Output Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Connecting a Tachometer Input Signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Connecting a Gate Input Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

5

Contents
Chapter 4: Verifying the Operation of a Module (Windows Only) . . . . . . . . . . . . . . . 49
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Select the Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Acquire Data from an Analog Output Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Configure the Analog Output Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Configure the Analog Input Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Configure the Recording Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Configure the Acquisition Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Start the Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Part 2: Using Your Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Chapter 5: Principles of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Block Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Analog Input Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Analog Input Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Input Ranges and Gains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
IEPE Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Input Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Input Clock Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Analog Input Conversion Modes (Windows Only). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Single-Value Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Single-Values Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Continuous Scan Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Input Triggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Specifying Input Triggers in Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Specifying Input Triggers in Linux or macOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Data Format and Transfer (Windows Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Error Conditions (Windows Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Analog Output Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Analog Output Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Output Ranges and Gains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Output Resolution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Output Clocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Output Conversion Modes (Windows Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Single-Value Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Waveform Generation Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Continuous Analog Output Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Reading Back the Analog Output Value (DT9837A Only) . . . . . . . . . . . . . . . . . . . . . . . 80
Output Trigger. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Data Format and Transfer (Windows Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Error Conditions (Windows Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

6

Contents
Tachometer Input Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Frequency or Period Measurements – Tachometer Counter 0 . . . . . . . . . . . . . . . . . . . . 82
Reading Tachometer Counter 0 Using Windows . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Reading Tachometer 0 Using in Linux or macOS . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Phase Measurements – Tachometer Counter 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Gate Input Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Triggering Acquisition on Multiple Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Synchronizing Acquisition on Multiple DT9837A, DT9837B, or DT9837C Modules . . . . 87
Chapter 6: Supported Device Driver Capabilities (Windows Only). . . . . . . . . . . . . . 91
Data Flow and Operation Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Buffering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Triggered Scan Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Data Encoding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Current and Resistance Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Thermocouple, RTD, and Thermistor Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
IEPE Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Bridge and Strain Gage Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Start Triggers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Reference Triggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Clocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Counter/Timers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Tachometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Chapter 7: Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
General Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
If Your Module Needs Factory Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Chapter 8: Calibration (Windows Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Using the Calibration Utility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Calibrating the Analog Input Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Connecting a Precision Voltage Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Using the Auto-Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Using the Manual Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Calibrating the Analog Output Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

7

Contents
Appendix A: Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Analog Input Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Analog Output Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Tachometer Input Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Gate Input Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Trigger Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
Master Oscillator Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Power, Physical, and Environmental Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Regulatory Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Connector Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
Appendix B: Connector Pin Assignments and LED Status Indicators . . . . . . . . . 131
RJ45 (LVDS) Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Gate Input Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
LED Status Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
Appendix C: Register-Level Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
DT9837 Register-Level Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Writing to the General Control Register 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Writing to EEPROM to Change the Coupling Type and Current Source . . . . . . . . . 137
Writing to EEPROM to Change the High Power Mode . . . . . . . . . . . . . . . . . . . . . . . . 138
DT9837A, DT9837B, and DT9837C Register-Level Programming . . . . . . . . . . . . . . . . . . . 140
Writing to the General Control Register 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
Writing to EEPROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
Appendix D: Programming in Linux or macOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Installing UL for Linux . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Using UL for Linux . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Channel Numbering in UL for Linux. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
IEPE Settings for Analog Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Tachometer Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Frequency and Period Measurement - Tachometer Counter 0 . . . . . . . . . . . . . . 147
Phase Measurements – Tachometer Counter 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
Gate Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
Power Mode Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Input Triggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Reading Back the Value of the Analog Output Channel. . . . . . . . . . . . . . . . . . . . . . . . 152
Synchronizing Acquisition on Multiple Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

8About this Manual
The DT9837 Series includes the DT9837, DT9837A, DT9837B, and DT9837C modules. The firstpart of this manual describes how to install and set up your DT9837 Series module and device
driver, and verify that your module is working properly.
The second part of this manual describes the features of the DT9837 Series modules and thecapabilities of the DT9837 Series Device Drivers in Windows. Troubleshooting and calibration
information is also provided.

Intended Audience
This document is intended for engineers, scientists, technicians, or others responsible forusing and/or programming a DT9837 Series module for data acquisition operations. It is
assumed that you have some familiarity with data acquisition principles and that you
understand your application.

Note: The majority of this manual assumes that you are using DT-Open Layers in Windows
to communicate with your device. If you want to program your device using the Linux ormacOS operating system, disregard the Windows usage sections in this manual and refer toAppendix D starting on page 145.

How this Manual is OrganizedThis manual is organized as follows:• Chapter 1, “Overview,” describes the major features of the DT9837 Series modules, aswell as the supported software and accessories for the modules.
• Chapter 2, “Setting Up and Installing the Module,” describes how to install a DT9837
Series module, how to apply power to the module, and how to configure the DT9837
Series Device Drivers in Windows.
• Chapter 3, “Wiring Signals,” describes how to wire signals to a DT9837 Series module.
• Chapter 4, “Verifying the Operation of a Module (Windows Only),” describes how toverify the operation of a DT9837 Series module with the Quick DataAcq application in
Windows.
• Chapter 5, “Principles of Operation,” describes all of the features of the DT9837 Series
modules and how to access them in your application.
• Chapter 6, “Supported Device Driver Capabilities (Windows Only),” lists the dataacquisition subsystems and the associated features accessible using the DT9837 Series
Device Drivers in Windows.
• Chapter 7, “Troubleshooting,” provides information that you can use to resolve problems
with the DT9837 Series modules and DT9837 Series Device Driver, should they occur.

9

About this Manual• Chapter 8, “Calibration (Windows Only),” describes how to calibrate the analog I/Ocircuitry of the DT9837 Series modules in Windows.
• Appendix A, “Specifications,” lists the specifications of the DT9837 Series modules.
• Appendix B, “Connector Pin Assignments and LED Status Indicators,” lists the pin
assignments of the connectors on the DT9837 Series modules.
• Appendix C, “Register-Level Programming,” describes the registers for the DT9837 Series
modules.
• Appendix D, “Programming in Linux or macOS,” provides information aboutprogramming the DT9837A, DT9837B, and DT9837C modules using the Linux or macOS
operating systems rather than Windows.
• An index completes this manual.

Conventions Used in this Manual
The following conventions are used in this manual:• Notes provide useful information or information that requires special emphasis, cautions
provide information to help you avoid losing data or damaging your equipment, andwarnings provide information to help you avoid catastrophic damage to yourself or yourequipment.
• Items that you select or type are shown in bold.

Related Information
Refer to the following documents for more information on using the DT9837 Series modules:• QuickDAQ User’s Manual (UM-24774). This manual describes how to create a QuickDAQ
application to acquire and analyze data from a DT-Open Layers data acquisition module
in Windows.
• DT-Open Layers for .NET User’s Manual (UM-22161). For programmers who are developing
their own application programs using Visual C# or Visual Basic .NET for Windows, thismanual describes how to use the DT-Open Layers for .NET Class Library to access thecapabilities of Data Translation data acquisition devices.
• DataAcq SDK User’s Manual (UM-18326). For programmers who are developing their own
application programs using the Microsoft C compiler in Windows, this manual describes
how to use the DT-Open Layers DataAcq SDK to access the capabilities of Data
Translation data acquisition devices.
• LV-Link Online Help. This help file describes how to use LV-Link with the LabVIEW
graphical programming language to access the capabilities of Data Translation dataacquisition devices in Windows.
• UL for Linux Online Help (https://github.com/mccdaq/uldaq). This help file describes
how to use the Universal Library from Measurement Computing with the DT9837A,
DT987B, or DT9837C module using the Linux or macOS operating system.

10

About this Manual

Where To Get Help
Should you run into problems installing or using a DT9837 Series module, the TechnicalSupport Department is available to provide technical assistance. Refer to Chapter 7 for more
information. If you are outside the United States or Canada, call your local distributor, whose
number is listed on our web site (www.mccdaq.com).

11

About this Manual12

1Overview
Hardware Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Supported Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Supported Accessories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Getting Started Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

13

Chapter 1

Hardware Features
The DT9837, DT9837A, DT9837B, and DT9837C are high-performance, multifunction dataacquisition modules for the USB (Ver. 2.0 or Ver. 1.1) bus.
Table 1 lists the major differences among the modules.
Table 1: Major Differences Among the DT9837 Series Modules
FeatureDT9837

DT9837A

DT9837B

DT9837C

Connectors

BNC

BNC

BNC

BNC (on the DT9837C-BNC) or
Mini XLR (on the DT9837C-XLR)

Maximum A/D Throughput

52.734 kHz

52.734 kHz

105.469 kHz

105.469 kHz

AC Coupling at –3 dB

0.5 Hz0.1 Hz0.5 Hz

1 Hz

Current Source

4 mA

4 mA

4 mA

2 mA

A/D Threshold Triggera

Fixed

Programmable

Programmable

Programmable

Number of Tachometer Counters

12 (C/T 0 and 1)

2 (C/T 0 and 1)

0

Number of Gate Inputs0

1b (C/T 2)

1c (C/T 2)

0

Number of Analog Output
Channels

1

1

0

1

Analog Output Readback
Capability

No

Yes

No

No

Maximum Analog Output
Throughput

46.875 kHz(fixed)52.734 kHz–

96 kHzAnalog Output Voltage

10 V @ 1 mA

10 V @ 3 mA–

±3 V @ 2 mA

Analog Output Trigger Types

Software trigger
only

Software trigger,
external digital trigger

None

Software trigger,
external digital trigger

RJ45 Synchronization Connector

No

Yes

Yes

Yes

a. For the start trigger on the DT9837, the threshold channel is channel 0 and the threshold level is fixed at 1.0 V.
For the start trigger on the DT9837A and DT9837B, the threshold channel is channel 0 and the analog threshold level is programmable from 0.2 V to
9.8 V with 0.1 V of hysteresis.
For the start trigger on the DT9837C, the threshold channel can be any of the analog input channels and the threshold level is programmable between±10 V for a gain of 1 and ±1 V for a gain of 10.
For the reference trigger on all modules, the threshold channel can be any of the analog input channels and the threshold level is programmablebetween ±10 V for a gain of 1 and ± 1 V for a gain of 10.
b. Available on the DT9837A-OEM version.
c. Available through a BNC connector on the DT9837B module.

14

Overview

Key Features of the DT9837
Figure 1 shows the layout of the DT9837 module.

Figure 1: DT9837 Module

The key features of the DT9837 module are as follows:• Simultaneous analog input and waveform analog output operations• Analog input subsystem: Four, simultaneous 24-bit A/D converters
 Throughput rate up to 52.734 kSamples/s for simultaneous, high-resolution
measurements
 Input range of ±10 V with software-selectable gains of 1 and 10 for an effective input
range of ±10 V and ±1 V
 Support for IEPE (Integrated Electronic Piezoelectric) inputs, including use of a 4 mAcurrent source and AC or DC coupling The ability to return the value of tachometer counter 0 in the analog input data stream,
allowing you to measure the period or frequency of the tachometer input signal
synchronously with analog input measurements
 Supports a start trigger for acquiring pre-trigger samples and a reference trigger for
acquiring post-trigger samples. You can specify the number of post-trigger samples toacquire before stopping the operation.
 For the start trigger, supports a software-programmable trigger source (software,
external digital trigger, or a positive-going analog threshold trigger on analog input
channel 0). The threshold level is fixed at 1.0 V for the analog threshold trigger.

15

Chapter 1
 For the reference trigger, supports a positive- or negative-going analog threshold
trigger on any of the analog input channels. You can program the threshold value from
–10 V to +10 V.
• Analog output subsystem: One 24-bit D/A converter Waveform capability of up to 8,192 sample
 Output rate of 46.875 kSamples/s Output range of ±10 V
 A software trigger starts the analog output operation• Internal clock source (shared between the analog input and analog output subsystems)

Key Features of the DT9837A
Figure 2 shows the layout of the DT9837A module.

Figure 2: DT9837A Module

The key hardware features of the DT9837A module are as follows:• Simultaneous analog input and analog output operations (continuous or waveformmode)• Analog input subsystem: Four, simultaneous 24-bit A/D converters
 Throughput rate up to 52.734 kSamples/s for simultaneous, high-resolution
measurements

16

Overview
 Input range of ±10 V with software-selectable gains of 1 and 10 for an effective input
range of ±10 V and ±1 V
 Support for IEPE (Integrated Electronic Piezoelectric) inputs, including use of a 4 mAcurrent source with 18 V compliance voltage for AC or DC coupling The ability to return the value of tachometer counter 0 in the analog input data stream,
allowing you to measure the period or frequency of the tachometer input signal
synchronously with analog input measurements
 The ability to read the value of tachometer counter 1 in the analog input data stream,
allowing you to precisely correlate tachometer measurements with analog input
measurements
 Optional OEM version of this module, called the DT9837A-OEM, supports the ability
to read the value of gate counter 2 in the analog input data stream, allowing you toprecisely correlate gate input measurements with analog input measurements
 Supports reading analog output values in the analog input data stream, allowing you
to correlate input and output values
 Supports a start trigger for acquiring pre-trigger samples and a reference trigger for
acquiring post-trigger samples. You can specify the number of post-trigger samples toacquire before stopping the operation.
 For the start trigger, supports a software-programmable trigger source (software,
external digital trigger, or a positive-going analog threshold trigger on analog input
channel 0). You can program the analog input threshold value from 0.2 V to 9.8 V with
0.1 V of hysteresis.
 For the reference trigger, supports a positive- or negative-going analog threshold
trigger on any of the analog input channels. You can program the threshold value from
–10 V to +10 V.
• Analog output subsystem: One 24-bit D/A converter Single value, waveform, and continuous streaming output
 Programmable output rate from 10 kSamples/s to 52.734 kSamples/s Output range of ±10 V
 Software-programmable trigger source (software trigger, external digital trigger, or
analog threshold trigger) to start the analog output operation.
• Internal clock source (shared between the analog input and analog output subsystems)• RJ45 synchronization (LVDS) connector for synchronizing acquisition on up to four
DT9837A modules

17Chapter 1

Key Features of the DT9837B
Figure 3 shows the layout of the DT9837B module.

Figure 3: DT9837B Module

The key hardware features of the DT9837B module are as follows:• Four, simultaneous 24-bit A/D converters• Internal clock source with a throughput rate up to 105.469 kSamples/s for simultaneous,
high-resolution analog input measurements• Input range of ±10 V with software-selectable gains of 1 and 10 for an effective input
range of ±10 V and ±1 V
• Support for IEPE (Integrated Electronic Piezoelectric) inputs, including use of a 4 mAcurrent source with 18 V compliance voltage for AC or DC coupling• The ability to return the value of tachometer counter 0 in the analog input data stream,
allowing you to measure the period or frequency of the tachometer input signal
synchronously with analog input measurements• The ability to read the value of tachometer counter 1 in the analog input data stream,
allowing you to precisely correlate tachometer measurements with analog input
measurements• The ability to read the value of gate counter 2 in the analog input data stream, allowing
you to precisely correlate gate input measurements with analog input measurements

18

Overview• Supports a start trigger for acquiring pre-trigger samples and a reference trigger for
acquiring post-trigger samples. You can specify the number of post-trigger samples toacquire before stopping the operation.
• For the start trigger, supports a software-programmable trigger source (software, external
digital trigger, or a positive-going analog threshold trigger on analog input channel 0).
You can program the analog input threshold value from 0.2 V to 9.8 V with 0.1 V ofhysteresis.
• For the reference trigger, supports a positive- or negative-going analog threshold trigger
on any of the analog input channels. You can program the threshold value from –10 V to
+10 V.
• RJ45 synchronization (LVDS) connector for synchronizing acquisition on up to four
DT9837B modules

Key Features of the DT9837C
Figure 4 shows the layout of DT9837C module. The model shown is the board-level, OEMversion with mini-XLR connectors.

Figure 4: DT9837C Module

19

Chapter 1
The key hardware features of the DT9837C module are as follows:• Simultaneous analog input and analog output operations (continuous or waveformmode)• Mini-XLR connectors (on the DT9837C-XLR) or BNC connectors (on the DT9837C-BNC)
for connecting audio inputs• Analog input subsystem: Four, simultaneous 24-bit A/D converters
 Throughput rate up to 105.469 kSamples/s for simultaneous, high-resolution
measurements
 Input range of ±10 V with software-selectable gains of 1 and 10 for an effective input
range of ±10 V and ±1 V
 Support for IEPE (Integrated Electronic Piezoelectric) inputs, including use of a 2 mAcurrent source with 18 V compliance voltage for AC and DC coupling 1 Hz high-pass filter
 Supports a start trigger for acquiring pre-trigger samples and a reference trigger for
acquiring post-trigger samples. You can specify the number of post-trigger samples toacquire before stopping the operation.
 For the start trigger, supports a software-programmable trigger source (software,
external digital trigger, or analog threshold trigger). You can program the analog input
threshold trigger to come from any analog input channel, to be positive- or
negative-going, and to have a threshold value from –10 V to +10 V.
 For the reference trigger, supports a positive- or negative-going analog threshold
trigger on any of the analog input channels. You can program the threshold value from
–10 V to +10 V.
• Analog output subsystem: One 24-bit D/A converter Single value, waveform, and continuous streaming output
 Programmable output rate from 10 kSamples/s to 96 kSamples/s Output range of ±3 V
 ±2 mA output current
 Software-programmable trigger type (software trigger, external digital trigger, or
analog threshold trigger) to start the analog output operation.
• Internal clock source (shared between the analog input and analog output subsystems)• RJ45 synchronization (LVDS) connector for synchronizing acquisition on up to four
DT9837C modules

20OverviewSupported SoftwareThis section describes compatible software for the Windows, Linux, and macOS operating
systems.

Windows Software
The following software is available for use with the DT9837 Series modules in Windows andis included on the Data Acquisition OMNI CD:• DT9837 Series Device Drivers – Two device drivers are provided in the DT9837 Series:
one for the DT9837 module and one for the DT9837A, DT9837B, and DT9837C modules.
The DT9837 Series Device Drivers allow you to use a DT9837, DT9837A, DT9837B, orDT9837C module with any of the supported software packages or utilities.
• DT9837 Series Calibration Utility – This utility, described in Chapter 8 starting on page
111, allows you to calibrate the analog input and analog output circuitry of a DT9837
Series module.
• QuickDAQ Base Version – The base version of QuickDAQ is free-of-charge and allows
you to acquire and analyze data from all Data Translation USB and Ethernet devices,
except the DT9841 Series, DT9817, DT9835, and DT9853/54. Using the base version of
QuickDAQ, you can perform the following functions: Discover and select your devices.
 Configure all input channel settings for the attached sensors.
 Load/save multiple hardware configurations.
 Generate output stimuli (fixed waveforms, swept sine waves, or noise signals).
 On each supported data acquisition device, acquire data from all channels supported
in the input channel list.
 Choose to acquire data continuously or for a specified duration.
 Choose software or triggered acquisition.
 Log acquired data to disk in an .hpf file.
 Display acquired data during acquisition in either a digital display using the Channel
Display window or as a waveform in the Channel Plot window.
 Choose linear or logarithmic scaling for the horizontal and vertical axes.
 View statistics about the acquired data, including the minimum, maximum, and meanvalues and the standard deviation in the Statistics window.
 Export time data to a .csv or .txt file; you can open the recorded data in Microsoft
Excel® for further analysis.
 Read a previously recorded .hpf data file.
 Customize many aspects of the acquisition, display, and recording functions to suit
your needs, including the acquisition duration, sampling frequency, trigger settings,
filter type, and temperature units to use.

21

Chapter 1• QuickDAQ FFT Analysis Option – When enabled with a purchased license key, theQuickDAQ FFT Analysis option includes all the features of the QuickDAQ Base version
with the FFT Analysis option plus basic FFT analysis features, including the following: The ability to switch between the Data Logger time-based interface and the FFT
Analyzer block/average-based interface.
 Supports software, freerun, or triggered acquisition with accept and reject controls for
impact testing applications.
 Allows you to perform single-channel FFT (Fast Fourier Transform) operations,
including AutoSpectrum, Spectrum, and Power Spectral Density, on the acquired
analog input data. You can configure a number of parameters for the FFT, including
the FFT size, windowing type, averaging type, integration type, and so on.
 Allows you to display frequency-domain data as amplitude or phase.
 Supports dB or linear scaling with RMS (root mean squared), peak, and peak-to-peakscaling options
 Supports linear or exponential averaging with RMS, vector, and peak hold averaging
options.
 Supports windowed time channels.
 Supports the following response window types: Hanning, Hamming, Bartlett,Blackman, Blackman Harris, and Flat top.
 Supports the ability to lock the waveform output to the analysis frame time.
 Allows you to configure and view dynamic performance statistics, including the input
below full-scale (IBF), total harmonic distortion (THD), spurious free dynamic range(SFDR), signal-to-noise and distortion ratio (SINAD), signal-to-noise ratio (SNR), andthe effective number of bits (ENOB), for selected time-domain channels in the Statistics
window.
 Supports digital IIR (infinite impulse response) filters.
• QuickDAQ Advanced FFT Analysis Option – When enabled with a purchased software
license, the QuickDAQ Advanced FFT Analysis option includes all the features of the
QuickDAQ Base version with the FFT Analysis option plus advanced FFT analysis
features, including the following: Allows you to designate a channel as a Reference or Response channel.
 Allows you to perform two-channel FFT analysis functions, including Frequency
Response Functions (Inertance, Mobility, Compliance, Apparent Mass, Impedance,
Dynamic Stiffness, or custom FRF) with H1, H2, or H3 estimator types,
Cross-Spectrum, Cross Power Spectral Density, Coherence, and Coherent Output
Power.
 Supports the Exponential response window type.
 Supports the following reference window types: Hanning, Hamming, Bartlett,Blackman, Blackman Harris, FlatTop, Exponential, Force, and Cosine Taper windows.
 Supports real, imaginary, and Nyquist display functions.
 Allows you to save data in the .uff file format.

22

Overview• Quick DataAcq application –The Quick DataAcq application provides a quick way to getup and running using a DT9837 Series module. Using this application, you can verify key
features of the modules, display data on the screen, and save data to disk. (Note that thisapplication does not support configuring AC/DC coupling or the excitation current
source for IEPE inputs.)• DT-Open Layers for .NET Class Library – Use this class library if you want to use Visual
C# or Visual Basic for .NET to develop your own application software for a DT9837 Series
module using Visual Studio 2003-2012; the class library complies with the DT-Open
Layers standard.
• DataAcq SDK – Use the Data Acq SDK if you want to use Visual Studio 6.0 and Microsoft
C or C++ to develop your own application software for a DT9837 Series module using
Windows Vista, Windows 7, or Windows 8; the DataAcq SDK complies with the DT-Open
Layers standard.
• DAQ Adaptor for MATLAB – Data Translation’s DAQ Adaptor provides an interface
between the MATLAB Data Acquisition (DAQ) subsystem from The MathWorks andData Translation’s DT-Open Layers architecture.
• LV-Link – A link to LV-Link is included on the Data Acquisition OMNI CD. Use LV-Link
if you want to use the LabVIEW graphical programming language to access thecapabilities of the DT9837 Series module.
Refer to the web site (www.mccdaq.com) for information about selecting the right software
package for your needs.

Linux or macOS Software
If you want to program the DT9837A, DT9837B, or DT9837C in Linux or macOS, the Universal
Library (UL) for Linux available from Measurement Computing Corporation is available.
Refer to Appendix D starting on page 145 for more information about using UL for Linux.

23Chapter 1

Supported Accessories
The EP386 panel, shown in Figure 5, is available for use with the DT9837A, DT9837B, andDT9837C modules.

Figure 5: EP386 Panel

This RJ45 distribution panel contains four RJ45 connectors that are wired in parallel, making it
useful when attaching up to four DT9837A, DT9837B, or DT9837C modules together. Refer topage 88 for more information on using this panel.

Note: You must have revision H or later of the DT9837A module or revision F or later of theDT9837A-OEM module to be able to attach four modules together. You can identify therevision of your module by looking at the serial number label on your module.
If you have revision G or earlier of the DT9837A or revision E or earlier of theDT9837A-OEM, you can attach a maximum of two modules together.

24

Overview

Getting Started Procedure
The flow diagram shown in Figure 6 illustrates the steps needed to get started using a DT9837
Series module. This diagram is repeated in each Getting Started chapter; the shaded area inthe diagram shows you where you are in the getting started procedure.

Set Up and Install the Module(see Chapter 2 starting on page 29)
Wire Signals(see Chapter 3 starting on page 39)

Verify the Operation of the Module (Windows Only)(see Chapter 4 starting on page 49)

Figure 6: Getting Started Flow Diagram

25

Chapter 1

26

Part 1: Getting Started

2
Setting Up and Installing the Module
Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
System Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Attaching Modules to the Computer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Configuring the DT9837 Series Device Drivers (Windows Only). . . . . . . . . . . . . . . . . . . . . 36

29

Chapter 2

Set Up and Install the Module(this chapter)
Wire Signals(see Chapter 3 starting on page 39)

Verify the Operation of the Module (Windows Only)(see Chapter 4 starting on page 49)

30

Setting Up and Installing the Module

UnpackingOpen the shipping box and verify that the following items are present:• DT9837, DT9837A, DT9837B, or DT9837C module• EP365 USB cable• Data Acquisition OMNI CD-ROM (needed only if you are programming in Windows)
If an item is missing or damaged, contact Data Translation. If you are in the United States, callthe Customer Service Department at (508) 956-5100. An application engineer will guide you
through the appropriate steps for replacing missing or damaged items. If you are locatedoutside the United States, call your local distributor (see www.mccdaq.com for more
information).

Note: The DT9837 Series modules are factory-calibrated. If you decide that you want torecalibrate the analog input or analog output circuitry in Windows, refer to the instructionsin Chapter 8.

31

Chapter 2

System Requirements
If you are using Windows, ensure that your computer meets the following system
requirements:• Processor: Pentium 4/M or equivalent• RAM: 1 GB
• Screen Resolution: 1024 x 768 pixels• Operating System: Windows 10, Windows 8, Windows 7, Windows Vista (32- and 64-bit)• Disk Space: 4 GB
If you are using Linux or macOS, refer to https://github.com/mccdaq/uldaq for information
on supported Linux and macOS distributions.

32Setting Up and Installing the Module

Attaching Modules to the ComputerThis section describes how to attach a DT9837 Series module to the host computer.

Note: Most computers have several USB ports that allow direct connection to USB devices.
If your application requires more DT9837 Series modules than you have USB ports for, you
can expand the number of USB devices attached to a single USB port by using expansion
hubs. For more information, refer to page 34.
You can unplug a module, then plug it in again, if you wish, without causing damage. This
process is called hot-swapping. Your application may take a few seconds to recognize amodule once it is plugged back in.
The DT9837 Series modules use less than 500 mA; therefore, they do not require an external
power supply.

You must install the device driver for your module before connecting the module(s) to thehost computer. If you are using Windows, run the installation program on your Data
Acquisition OMNI CD to install the device driver and other software for the module. If you
are using Linux or macOS, refer to the instructions from github athttps://github.com/mccdaq/uldaq to build and install UL for Linux.

Connecting Directly to the USB Ports
To connect a DT983 Series module directly to a USB port on your computer, do the following:
1. Attach one end of the USB cable to the USB port on the module.
2. Attach the other end of the USB cable to one of the USB ports on the host computer, as
shown in Figure 7.
The operating system automatically detects the USB module.

DT9837 Series Module

USB Ports

Host Computer
USB Cable

Figure 7: Attaching the Module to the Host Computer

33

Chapter 2
3. For Windows Vista only:
a. Click Locate and install driver software (recommended).
The popup message "Windows needs your permission to continue" appears.
b. Click Continue.
The Windows Security dialog box appears.
c.

Click Install this driver software anyway.

4. Repeat these steps to attach another DT9837 Series module to the host computer, if
desired.

Note: Once you have connected your module to the host computer, power is turned on to
the module when your application program opens the module. The LED on the module turns
green to indicate that power is turned on.
Power is turned off to the module when your application program terminates its connection
to the module.

Connecting to an Expansion Hub
Expansion hubs are powered by their own external power supply. The practical number ofDT9837 Series modules that you can connect to a single USB port depends on the throughput
you want to achieve.
To connect multiple DT9837 Series modules to an expansion hub, do the following:
1. Attach one end of the USB cable to the module and the other end of the USB cable to an
expansion hub.
2. Connect the power supply for the expansion hub to an external power supply.
3. Connect the expansion hub to the USB port on the host computer using another USB
cable.
The operating system automatically detects the USB module.
4. For Windows Vista only:
a. Click Locate and install driver software (recommended).
The popup message "Windows needs your permission to continue" appears.
b. Click Continue.
The Windows Security dialog box appears.
c.

Click Install this driver software anyway.

5. Repeat these steps until you have attached the number of expansion hubs and modules
that you require. Refer to Figure 8.
The operating system automatically detects the USB devices as they are installed.

34

Setting Up and Installing the Module

DT9837 Series
ModuleDT9837 Series
ModuleUSB Cables

Host Computer
USB Cable

USB Cable
Power Supply
for Hub

Expansion Hubs
Power Supply
for Hub
DT9837 Series
ModuleDT9837 Series
ModuleUSB Cables

Figure 8: Attaching Multiple Modules Using Expansion Hubs

Note: Once you have connected your module to the host computer, power is turned on to
the DT9837 Series module when your application program opens the module. The LED on
the module turns green to indicate that power is turned on.
Power is turned off to the module when your application program terminates its connection
to the module.

35

Chapter 2

Configuring the DT9837 Series Device Drivers(Windows Only)
This section applies to Windows only. If you are using Linux or macOS, refer to Appendix D
starting on page 145 for more information.

Note: In Windows, you must have administrator privileges to run the Open Layers Control
Panel. When you double-click the Open Layers Control Panel icon, you may see the Program
Compatibility Assistant. If you do, select Open the control panel using recommended
settings. You may also see a Windows message asking you if you want to run the Open
Layers Control Panel as a "legacy CPL elevated." If you get this message, click Yes.
If you do not get this message and have trouble making changes in the Open Layers Control
Panel, right click the DTOLCPL.CPL file and select Run as administrator. By default, this fileis installed in the following location:
Windows (32-bit)
C:\Windows\System32\Dtolcpl.cpl
Windows (64-bit)
C:\Windows\SysWOW64\Dtolcpl.cpl

To configure the device driver for a DT9837 Series module in Windows, do the following:
1. If you have not already done so, power up the host computer and all peripherals.
2. From the Windows Start menu, select Settings|Control Panel.
3. From the Control Panel, double-click Open Layers Control Panel.
The Data Acquisition Control Panel dialog box appears.
4. If you want to rename the module, click the name of the module that you want to rename,click Edit Name, enter a new name for the module, and then click OK. The name is used
to identify the module in all subsequent applications.
5. Select the module that you want to configure, and then click Advanced.
The Measurement Options dialog box appears.
6. Check the Power Always On box if you want to enable high power mode or uncheck thisbox to disable high power mode (the default). Turning off the high-power circuitry helps
to conserve power, which may be useful when the module is used with a laptop.
However, to ensure that the module is warmed up and that any settling time errors of the
IEPE current source are minimized, it is recommended that you check this option to keep
the module’s high-power circuitry always turned on.

36Setting Up and Installing the Module
7. You can read the number of counts between two consecutive starting edges of thetachometer input signal by including channel 4 (tachometer counter 0) in the analog input
channel list. On the DT9837 module, the starting edge is always rising; on the DT9837A
and DT9837B modules, the starting edge is programmable (either rising or falling). See
page 82 for more information.
For the DT9837, skip to step 11. For the DT9837A and DT9837B modules, configure theTach.CT0 measurement parameters as follows:a. From the Start Select combo box, select the edge (Rising Edge or Falling Edge) of thetachometer input signal that you want to use to start the measurement.
b. From the Measure Mode combo box, select Zeros if you want to read a value of 0
between measurements, or select Previous Measurement if you want to read theprevious measurement value if the new measurement value is not yet complete.
c.

From the Stale Data combo box, select Used if you want to indicate whether or not
the measurement value if new, or select Not Used if you do not want to indicate
whether the measurement value is new. If you select Used, the most significant bit(MSB) of the measurement value is set to 0 when the value is new and set to 1 whenthe measurement is not yet complete. If you select Not Used, the MSB of themeasurement value is always 0.

8. On the DT9837A and DT9837B modules, you can measure the phase of the tachometer
input signal in relation to the A/D sample by specifying channel 5 (tachometer counter 1)
in the analog input channel list; see page 84 for more information. Configure the Tach.CT1
measurement parameters as follows:a. From the Start Select combo box, select the signal that you want to use to start themeasurement (A/D Sample, Tach Input Rising Edge, or Tach Input Falling Edge).
b. From the Stop Select combo box, select the signal that you want to use to stop themeasurement (A/D Sample, Tach Input Rising Edge, or Tach Input Falling Edge).
Note that if you choose to start the measurement using the A/D sample, choose atachometer edge to stop the measurement. Likewise, if you choose to stop themeasurement using the A/D sample, choose a tachometer edge to start themeasurement.
c.

From the Self Clear combo box, select Clear to zero if you want to return a value of 0
between measurements, or select Keep last Value if you want to return the previous
measurement value between readings.

37

Chapter 2
9. For the DT9837A-OEM and DT9837B modules, you can also measure the phase of the gate
input signal in relation to the A/D sample by specifying channel 6 (gate counter 2) in theanalog input channel list; see page 85 for more information. Configure the Gate.CT2
measurement parameters as follows:a. From the Start Select combo box, select the signal that you want to use to start themeasurement (A/D Sample, Gate Rising Edge, or Gate Falling Edge).
b. From the Stop Select combo box, select the signal that you want to use to stop themeasurement (A/D Sample, Gate Rising Edge, or Gate Falling Edge).
Note that if you choose to start the measurement using the A/D sample, choose a gateedge to stop the measurement. Likewise, if you choose to stop the measurement using
the A/D sample, choose a gate edge to start the measurement. If you choose the startand stop the measurement using the same gate edge, you will measure the pulse
width of the gate signal; be aware that the stopping edge does not restart themeasurement; the next starting edge will start the next measurement.
c.

From the Self Clear combo box, select Clear to zero if you want to return a value of 0
between measurements, or select Keep last Value if you want to return the previous
measurement value between readings.

10. For the Coupling type, select AC for AC coupling or DC for DC coupling.
11. For the Current Source, select Enabled to enable the internal excitation current source or
Disabled to disable the internal excitation current source.
Note: If you enable the use of the internal excitation current source, it is recommended
that you choose AC coupling. Refer to page 44 for more information on wiring IEPE
inputs.
12. When you are finished, click OK to close the Measurement Options dialog box.
13. Repeat steps 4 to 11 for the other modules that you want to configure.
14. When you are finished configuring the modules, click Close to close the Control Panel.

Note: If you need to configure these settings programmatically instead of using the Open
Layers Control Panel, you can write to the registers of the module (see Appendix C startingon page 135) or you can use UL for Linux (see Appendix D starting on page 145).

38

3
Wiring Signals
Preparing to Wire Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Connecting Analog Input Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Connecting an Analog Output Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Connecting a Tachometer Input Signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Connecting a Gate Input Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

39

Chapter 3

Set Up and Install the Module(see Chapter 2 starting on page 29)
Wire Signals(this chapter)

Verify the Operation of the Module (in Windows)(see Chapter 4 starting on page 49)

40

Wiring Signals

Preparing to Wire Signals
This section provides recommendations and information about wiring signals to a DT9837
Series module.

Wiring Recommendations
Keep the following recommendations in mind when wiring signals to a DT9837 Series
module:• Follow standard ESD procedures when wiring signals to the module.
• Separate power and signal lines by using physically different wiring paths or conduits.
• To avoid noise, do not locate the module and cabling next to sources that produce highelectromagnetic fields, such as large electric motors, power lines, solenoids, and electricarcs, unless the signals are enclosed in a mumetal shield.
• Prevent electrostatic discharge to the I/O while the module is operational.
• Connect all unused analog input channels to analog ground.

Wiring Signals to the Module
The DT9837 module contains five BNC connectors on one end of the module, and two BNC
connectors and a USB connector on the other end of the module as shown in Figure 9.

USB Port
Analog Inputs

Analog Output
External
Trigger

Tachometer

Figure 9: Connectors on the DT9837 Module

41

Chapter 3
The DT9837A module, shown in Figure 10, provides all of these connectors and an additional
RJ45 LVDS connector for connecting multiple modules. The OEM version of the DT9837A,
shown in Figure 17 on page 47, also provides an additional gate input connector.

USB Port

RJ45 (LVDS) Port

Analog Inputs

Analog Output

Tachometer

External Trigger

Figure 10: Connectors on the DT9837A Module

Figure 11 shows the connectors on the DT9837B module.

USB Port

Analog Inputs

RJ45 (LVDS) Port
Gate Input

Tachometer

External Trigger

Figure 11: Connectors on the DT9837B Module42

Wiring Signals
Figure 12 shows the connectors on the DT9837C-BNC module (the board-level, OEM versionof the module is shown).

USB Port
AnalogInputs
RJ45 (LVDS) Port
Analog Output

External Trigger

Figure 12: Connectors on the DT9837C-BNC Module

Figure 13 shows the connectors on the DT9837C-XLR module (the board-level, OEM versionof the module is shown).

USB Port
AnalogInputs

RJ45 (LVDS) Port
Analog Output

External Trigger

Figure 13: Connectors on the DT9837C-XLR Module

The remaining sections of this chapter describe how to attach signals to these connectors.

43

Chapter 3

Connecting Analog Input Signals
You can connect up to four analog input signals (or IEPE sensors) to the BNC connectors on a
DT9837 Series module. Internally, these signals are connected in single-ended mode. The
DT9837 Series modules support an input signal range of ±10 V (using a gain of 1) or ±1 V
(using a gain of 10).

Note: If you enable the use of the internal excitation current source for IEPE inputs, it isrecommended that you choose AC coupling. Refer to page 68 for more information on IEPE
inputs.

Figure 14 shows how to connect analog inputs (channels 0 and 1, in this case) to the connectors
on the DT9837 Series modules.

DT9837 Series Module
Analog In 0
SignalSourceAnalog In 1

Figure 14: Connecting Analog Inputs to a DT9837 Series Module

44

Wiring Signals

Connecting an Analog Output Signal
The DT9837, DT9837A, and DT9837C modules provide one analog output channel. Figure 15
shows how to connect an analog output signal to the DT9837, DT9837A, or DT9837C module.

DT9837, DT9837A, or
DT9837C Module

Analog Out 0

Load

Note that the connector
automatically connects theAnalog Ground signal

Figure 15: Connecting an Analog Output Signal to a
DT9837, DT9837A, or DT9837C Module

45

Chapter 3

Connecting a Tachometer Input Signal
You can connect a ±30 V tachometer input signal to the tachometer input BNC on a DT9837,
DT9837A, or DT9837B module, as shown in Figure 16.

DT9837 DT9837A, or
DT9837B Module

SignalSourceTachometer In 0

Figure 16: Connecting a Tachometer Input Signal to a DT9837, DT9837A, or DT9837B Module46

Wiring Signals

Connecting a Gate Input Signal
The DT9837A-OEM module provides a 4-pin Gate Input connector for measuring period,
frequency, and pulse width values. The DT9837B provides a BNC connector for attaching agate input signal. Figure 17 shows how to connect a TTL gate input signal to theDT9837A-OEM module.

DT9837A-OEM Module

4

Gate Input
Connector

1

J12

DigitalGroundGate Input

External
SourceFigure 17: Connecting a Gate Input Signal to the DT9837A-OEM Module

47

Chapter 3
Figure 18 shows how to attach a TTL gate input signal to a DT9837B module.

DT9837B Module

Gate Input

SignalSourceNote that the BNC automaticallyconnects the Digital Groundsignal appropriately.

Figure 18: Connecting a Gate Input Signal to a DT9837B Module48

4
Verifying the Operation of a Module(Windows Only)
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Select the Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Acquire Data from an Analog Output Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

49

Chapter 4

Set Up and Install the Module(see Chapter 2 starting on page 29)
Wire Signals(see Chapter 3 starting on page 39)

Verify the Operation of the Module (Windows Only)(this chapter)50

Verifying the Operation of a Module (Windows Only)

Overview
Note: This chapter applies only if you are using a DT9837 Series device in Windows.

You can verify the operation of a DT9837 Series module using the QuickDAQ application.
QuickDAQ allows you to acquire and analyze data from all Data Translation USB and
Ethernet devices, except the DT9841 Series, DT9817, DT9835, and DT9853/54. This chapter
describes how to verify the operation of a DT9837 Series module using the QuickDAQ baseversion.

51

Chapter 4

Select the Device
To get started with your DT9837 Series module and the QuickDAQ application, follow thesesteps:
1. Connect the DT9837 Series module to the USB port of your computer, and connect yoursensors to the module.
2. Start the QuickDAQ application.
The Device Selection window appears.

3. For the Device Family selection, select OpenLayersDevices.
By default, the application "discovers" all devices that are available for the specified
device family and displays the module name for the USB devices in the drop-down list. If
you want to refresh this list to determine if other devices are available, click Refresh.
4. Select the module name for the DT9837 Series module that you want to use from the list of
Available Devices, and click Add.
Information about the device, including the model number, serial number, firmware version, driver
version, and scanning status is displayed.

52

Verifying the Operation of a Module (Windows Only)

If you want to rename your device, do the following:a. Click the Row Selector button for the device.
b. Click the IP address or module name in the Name column to highlight it and enter ameaningful name to represent each available device.
5. If you are using multiple devices, you must configure one device as the clock and trigger
master, as follows:a. Click the Row Selector button for the device that you want to be the clock and trigger
master.
b. For the clock and trigger master device, check the box under the Master column.
6. (Optional) If you want to remove a device from list of selected devices, click the Row
Selector button for the device, and then click Remove.
7. Once you have added all the devices that you want to use with the application, click OK.
The latest state is saved and used when the application is next run; the interface of the QuickDAQ
application is displayed.

53

Chapter 4

54

Verifying the Operation of a Module (Windows Only)

Acquire Data from an Analog Output Channel
The following steps describe how to use the QuickDAQ application to monitor the output of
the analog output signal using an analog input channel.
In this example, a 3 V sine wave is output on analog output channel 0 of a DT9837C module.
The analog output channel is connected to analog input channel 0 on the DT9837C module.

Note: If you are using a DT9837B module, attach a voltage source of ±10 V to analog input
channel 0, and skip the next section on configuring the analog output settings.

Configure the Analog Output Settings
For this example, configure the analog output channel as follows:
1. Click the Output tab of the Acquisition and Config window.

55

Chapter 4
2. Select the Enable checkbox to enable the analog output channel on the module.
3. For the Waveform type, select Fixed.
4. For Peak Voltage, enter 3 to output a ±3 V signal.
5. For Offset, enter 0.
6. For Signal Type, select Sine to output a sine wave.
7. For Output Mode, select Continuous to output a waveform that repeats continuously.
8. For Frequency, select 10 Hz; this is the frequency of the output waveform.
9. For Ramp Up Time, enter 0.
10. For the Start/Stop Method, select With Acquisition.
The analog output operation will start when you start acquisition.
11. If desired, hide the Acquisition Config window by clicking the Auto-Hide pin (the top, right corner of the window.

) inConfigure the Analog Input Channel
Configure the analog input channel as follows:
1. Ensure that the output from analog output channel 0 is connected to the input of analog
input channel 0.
2. Configure the analog input channel by clicking the Input Channel Configuration toolbar
button () or by clicking the Configuration menu and clicking Input Channel
Configuration.
3. Enable analog input channel 0 by clicking the Enable checkbox next to the channel.

4. Under the Channel Name column, leave the default channel name as Ain 0.
5. Under the Range column, select the input range for analog input channel.
In this example, ±10 V is used.

56

Verifying the Operation of a Module (Windows Only)
6. Under the Coupling column, select the coupling type (AC or DC) for your sensor.
Since this example is monitoring a voltage input, DC is used.
7. Under the Current Source column, select whether to enable or disable use of the current
source on the data acquisition device.
Since this example is monitoring a voltage input, the Current Source checkbox is not checked(disabled) for the analog input channel.
8. Under the Engineering Units column, select the engineering units for the input.
In this example, V is used.
9. Enter the number of mV per engineering unit in the mV/EU field.
In this example, 1000 is used.
10. If an offset is specified for the input, enter the value in the EU Offset field.
In this example, no offset (0) is specified.
11. If desired, enter a test point value for the channel.
In this example, 1 is used.
12. If desired, enter a sensor direction for each channel.
In this example, the default value of X+ is used.
13. Click Close to close the Configure Devices dialog box.

57

Chapter 4

Configure the Recording Settings
For this example, configure the recording settings as follows:
1. Click the Recording tab of the Acquisition Config window.

2. For Filename generation, use the default Filename option.
3. For Filename, use the default name for the data file.
4. Leave the Enable Continuous Acquisition checkbox unchecked.
5. For Acquisition Duration, select 1 second.
The number of seconds for the total run and the amount of available disk space are shown.
6. For X Span Axis, select 1 second.

58

Verifying the Operation of a Module (Windows Only)

Configure the Acquisition Settings
For this example, configure the acquisition settings as follows:
1. Click the Acquisition tab of the Acquisition Config window.

2. For the Per Channel Sampling Frequency text box, enter 10000.
The sampling rate, sample interval, and number of scans are displayed.
3. For the Trigger Source check box, select Software to ensure that the measurement starts
as soon as the Record button is clicked.

59Chapter 4

Start the Operation
Once you have configured the channels and the application parameters, click the Record
toolbar button () or press the F5 key to start the operation.
Results similar to the following are displayed in the Channel Plot window, showing theoutput of analog output channel 0 as measured by analog input channel 0.

Note: Many additional options are provided in QuickDAQ for measuring and analyzing thedata. Refer to the QuickDAQ User’s Manual for detailed information.

60

Part 2: Using Your Module5
Principles of Operation
Block Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Analog Input Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Analog Output Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Tachometer Input Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Gate Input Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Triggering Acquisition on Multiple Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Synchronizing Acquisition on Multiple DT9837A, DT9837B, or DT9837C Modules . . . . 87

63

Chapter 5

Block Diagrams
Figure 19 shows a block diagram of the DT9837 module.

+18 V Compliance Voltage
4 mA Current
SourceAnalogInput 01M

Sigma-Deltas

x1, 1024-BitA/D

Clock

0.5 HzHighSpeed
USB 2.0
Interface

4 mA

AnalogInput 11M

x1, 1024-BitA/D

0.5 HzControl
Logic

4 mA

AnalogInput 2

1M

x1, 1024-Bit
A/D

8K
FIFO

24-BitD/A

0.5 Hz

USB
2.0

D/A
Output 0
10 kHzFilter

4 mA

AnalogInput 31M

x1, 1024-BitA/D

0.5 HzTachometer
Input

Figure 19: Block Diagram of the DT9837 Module

64

Ext Trigger

Principles of Operation
Figure 20 shows a block diagram of the DT9837A module.

+18 V Compliance Voltage
4 mA Current
SourceSigma-Deltas
24-BitA/D

AnalogInput 01M
0.1 Hz

8K
D/A
FIFO

x1,
10

2K
A/D
FIFO

4 mA
24-BitA/D
AnalogInput 11M
0.1 Hzx1,
10

Control
Logic

4 mA

USB
2.0

HighSpeed
USB 2.0
Interface

A/D
Clock

24-BitA/D
AnalogInput 21M
0.1 Hzx1,
10

Ext Trigger and Clock

4 mA
24-BitA/D
AnalogInput 31M
0.1 Hz

x1,
10

RJ45

D/A
Clock
D/A
Output 0
24-Bit D/A
SigmaDelta

10 kHzFilterTrigger
D/A
Readback

16-bitA/D
Ext Gate*

Tachometer
Input* The external gate input signal is provided on
the DT9837A-OEM module.

Ext Trigger

Figure 20: Block Diagram of the DT9837A Module

65

Chapter 5
Figure 21 shows a block diagram of the DT9837B module.

+18 V Compliance Voltage
4 mA Current
SourceSigma-Deltas
24-BitA/D

AnalogInput 01M
0.5 Hz

4K
A/D
FIFO

x1,
10

4 mA
24-BitA/D
AnalogInput 11M
0.5 Hz

x1,
10

A/D
Clock

USB
2.0

HighSpeed
USB 2.0
InterfaceControl
Logic

4 mA
24-BitA/D
AnalogInput 21M
0.5 Hzx1,
10

Ext Trigger and Clock

RJ45

4 mA
24-BitA/D
AnalogInput 31M
0.5 Hzx1,
10

Trigger

Ext Gate

Ext Trigger
Tachometer
Input

Figure 21: Block Diagram of the DT9837B Module66Principles of Operation
Figure 22 shows a block diagram of the DT9837C module.

+18 V Compliance Voltage
2 mA Current
SourceSigma-Deltas
24-BitA/D

AnalogInput 0

8K
D/A
FIFO

1M
x1, 10

1 Hz

2K
A/D
FIFO

2 mA
24-BitA/D
AnalogInput 11M
x1, 10

1 Hz

Control
Logic

2 mA

USB
2.0

HighSpeed
USB 2.0
Interface

A/D
Clock

24-BitA/D
AnalogInput 2

1M

Ext Trigger and Clockx1, 10

1 Hz
2 mA

24-BitA/D
AnalogInput 3

D/A
Clock
D/A
Output 0

1M
1 Hz

x1, 10RJ45

24-Bit D/A
SigmaDelta

40 kHzFilterTrigger

Ext Trigger

Figure 22: Block Diagram of the DT9837C Module

67

Chapter 5

Analog Input Features
This section describes the following features of analog input (A/D) subsystem on the DT9837
Series modules:• Analog input channels, described on this page
• IEPE functions, described on page 69• Input resolution, described on page 69• Input ranges and gains, described on page 68• Input sample clock sources, described on page 69• Analog input conversion modes, described on page 70• Input triggers, described on page 73• Data format and transfer, described on page 74• Error conditions, described on page 75

Analog Input Channels
The DT9837 Series modules support four, single-ended analog input channels (numbered 0 to3). All analog input channels are simultaneously clocked. If desired, you can connect IEPE
sensors to these inputs; refer to page 69 for more information on IEPE functions.

Note: To maintain simultaneous operation, all analog input connections must have the samelead lengths.

The DT9837 Series modules use Delta-Sigma analog-to-digital converters (ADCs) that provide
anti-aliasing filters based on the clock rate. These filters remove aliasing, which is a condition
where high frequency input components erroneously appear as lower frequencies after
sampling.

Input Ranges and GainsThe DT9837 Series modules provide an input range of ±10 V and software-selectable gains of 1
and 10. This provides effective input ranges of ±10 V (when the gain is 1) and ±1 V (when thegain is 10).

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Principles of Operation

IEPE Functions
Applications that require accelerometer, vibration, noise, or sonar measurements often use
IEPE sensors. IEPE conditioning is built-in to the analog input circuitry of the DT9837 Series
modules. The modules support the following software-programmable IEPE functions for eachof the four analog inputs:• Excitation current source – The DT9837, DT9837A, and DT9837B modules provide aninternal excitation current source of 4 mA. The DT9837C module provides an internal
excitation current source of 2 mA. You can enable or disable the use of a internal
excitation current source using software. By default, the excitation current source isdisabled.
• Coupling type – You can select whether AC coupling or DC coupling is used.
Note: If you enable the use of the internal excitation current source, it is recommended
that you choose AC coupling.
The DT9837C also provides a 1 Hz high-pass filter.
If you are using Windows, you can change the IEPE settings using the Open Layers Control
Panel applet, described on page 36, or by writing to the registers of the module, as describedon Appendix C starting on page 135. You can also use the Control Panel to keep the module’s
high-power circuitry always turned on to minimize any settling time errors related to the
IEPE current source. Refer to page 36 for more information.
If you are using Linux or macOS, refer to page 147 for information on programming the IEPE
settings.

Input Resolution
The resolution of the analog input channels is fixed at 24 bits; you cannot specify the
resolution in software.

Input Clock Source
The DT9837 Series modules support an internal clock, which is derived from the USB clock.
Use software to specify the internal clock source and the frequency at which to pace the input
and output operations and to start the sample clock. For the DT9837 and DT9837A, thesampling frequency ranges from 195.3 Hz to 52.734 kHz. For the DT9837B and DT9837C, thesampling frequency ranges from 195.3 Hz to 105.469 kHz.

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Note: According to sampling theory (Nyquist Theorem), specify a frequency that is at least
twice as fast as the input’s highest frequency component. For example, to accurately sample a
20 kHz signal, specify a sampling frequency of at least 40 kHz to avoid aliasing.
The modules support a wide pass band to eliminate aliasing, allowing you to measure low
frequency signals accurately at the Nyquist sampling rate.

The actual frequency that the module can achieve may be slightly different than the frequency
you specified due to the accuracy of the clock. You can determine the actual clock frequency
using software.
Internally, the value that you specify for the internal clock frequency is multiplied by 512 (forfrequencies of 52.734 kHz or less) or 256 (for frequencies greater than 52.734 kHz) to set theoscillator on the module. For example, if you specify an internal clock frequency of 50 kHz,the module sets the internal oscillator for the A/D converters to 25.6 MHz. The maximum
timebase is 27 MHz.
Once the sample clock is started, the module requires 39 clock pulses before the first A/Dconversion is completed (39/sample rate) due to the group delay of the converters. The
software automatically adjusts for the group delay to provide only valid data in each buffer.
The tachometer data (which does not have the 39 sample group delay) is synchronized withthe analog data stream. This is done through the firmware and device driver by caching thetachometer data and aligning it in time with the analog data in the user’s data buffers.

Analog Input Conversion Modes (Windows Only)
Note: This section applies to DT-Open Layers in Windows. If you are using Linux ormacOS, refer to the online help for UL for Linux (see https://github.com/mccdaq/uldaq) for
more information on supported modes of operation.

In Windows, DT9837 Series modules support single-value, single-values, and continuous scanconversion modes. This section describes each of these conversion modes.

Single-Value Operations
Single-value operations are simpler to use than continuous operations. Using software, you
specify the analog input channel (0, 1, 2, or 3) and the gain that you want to use. The module
acquires the data from the specified channel and returns the data immediately.
For single-value operations, you cannot specify a clock source, trigger source, scan mode, orbuffer. Single-value operations stop automatically when finished; you cannot stop asingle-value operation.

70

Principles of Operation

Note: You cannot read the value of tachometer counter 0 (described on page 82), tachometercounter 1 (described on page 84), gate counter 2 (described on page 85), or the analog output
readback channel (described on page 80) using a standard single-value operation. To readthese values, specify the channels as part of the analog input channel list using continuous
scan mode, described on page 71.

Single-Values Operations
If you prefer to read a single value from all the analog input channels simultaneously using
one software call, use a single-values operation. You specify the analog input subsystem andthe gain that you want to use for the channels (not the channels themselves). The module thenacquires a value from each input channel simultaneously; the data is returned as an array of
input values.

Note: For the DT9837, a single values operation also returns a valid value from tachometercounter 0 (analog input channel 4), described on page 82.
For the DT9837A and DT9837B, a single values operation returns values from the analog
input channels as well as from tachometer counter 0 (described on page 82), tachometercounter 1 (described on page 84), gate counter 2 (described on page 85), and the analog
output readback channel (for the DT9837A; described on page 80), but only the data fromanalog input channels 0 through 3 is valid. Use continuous scan mode, described next, toread valid data from the tachometer counters, gate counter, and analog output readback
channel.

For single-values operations, you cannot specify a clock source, trigger source, scan mode, orbuffer. Single-values operations stop automatically when finished; you cannot stop asingle-values operation.

Continuous Scan Mode
Continuous scan mode takes full advantage of the capabilities of the DT9837 Series modules.
You can specify a channel list, clock source, start trigger, reference trigger, post-trigger scancount, and buffer using software.
On the DT9837 module, you can enter up to 5 entries in the channel list, including four analog
input channels (A/D channel 0 to 3) and tachometer counter 0 (A/D channel 4), described on
page 82.
On the DT9837A module, you can enter up to 8 entries in the channel list, including four
analog input channels (A/D channels 0 to 3), tachometer counter 0 (A/D channel 4), describedon page 82, tachometer counter 1 (A/D channel 5), described on page 84, gate counter 2 (A/D
channel 6), described on page 85, and the analog output readback value (A/D channel 7),
described on page 80. Using software, specify the channels you want to sample in sequential
order.

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On the DT9837B module, you can enter up to 7 entries in the channel list, including four
analog input channels (A/D channels 0 to 3), tachometer counter 0 (A/D channel 4), describedon page 82, tachometer counter 1 (A/D channel 5), described on page 84, and gate counter 2(A/D channel 6), described on page 85. Using software, specify the channels you want tosample in sequential order.
On the DT9837C module, you can enter up to 4 entries in the channel list (analog input 0 to 3).
Using software, specify the channels you want to sample in sequential order.
When it detects the start trigger, the module samples all the channels in the list
simultaneously.
If a reference trigger is not specified, data that is acquired after the start trigger is post-trigger
data. The sampled data is placed in the allocated buffer(s). The operation continues until you
stop it or until no more buffers are available.
If a reference trigger is specified, data that is acquired after the start trigger is pre-trigger data;when the reference trigger occurs, pre-trigger data acquisition stops and post-trigger
acquisition starts at the next sample. The sampled data is placed in the allocated buffer(s). The
operation continues until the number of scans that you specify for the post-trigger scan counthave been acquired; at the point, the operation stops. Note that the sample at which the trigger
occurs is not counted as a post-trigger sample. Refer to page 73 for more information about
triggers.
The conversion rate is determined by the frequency of the input sample clock; refer to page 69
for more information about the input sample clock.
Using software, you can stop a scan by performing either an orderly stop or an abrupt stop. In
an orderly stop, the module finishes acquiring the current buffer, stops all subsequentacquisition, and transfers the acquired data to host memory; any subsequent triggers are
ignored. In an abrupt stop, the module stops acquiring samples immediately; the current
buffer is not completely filled, it is returned to the application only partially filled, and any
subsequent triggers are ignored.
To select continuous scan mode, use software to specify the following parameters:• Specify the data flow as Continuous• Specify the clock source as internal and specify the clock frequency (refer to page 69)• Specify the start trigger (refer to page 74)• Specify the reference trigger (refer to page 74)• Specify the post-trigger scan count (the number of post-trigger samples to acquire after
the reference trigger occurs)
Figure 23 illustrates continuous scan mode (using a start and reference trigger) with a channel
list of four entries: channel 0 through channel 3. In this example, pre-trigger analog input datais acquired when the start trigger is detected. When the reference trigger occurs, the specified
number of post-trigger samples (3, in this example) are acquired.

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Principles of Operation

Trigger Sample is not counted
as post-trigger sample
Post-Trigger Scan Count = 3

Input
SampleClock

Chan 2Chan 2Chan 2Chan 2Chan 2Chan 2Chan 1Chan 1Chan 1Chan 1Chan 1Chan 1Chan 0Chan 0Chan 0Chan 0Chan 0Chan 0Pre-trigger data acquired

Start Trigger occurs

3 Post-trigger samples acquired

Reference Trigger occurs

Figure 23: Continuous Scan Mode on the DT9837 Series Modules
Using a Start and Reference Trigger

Input Triggers
A trigger is an event that occurs based on a specified set of conditions. The DT9837 Series
modules support the following input triggers:• Software trigger – A software trigger occurs when you start the analog input operation insoftware (the computer issues a write to the module to begin conversions).
• External digital (TTL) trigger – An external digital (TTL) trigger occurs when the module
detects a rising-edge transition on the signal connected to the Ext Trig connector on themodule.
• Analog threshold trigger – For the DT9837 module, the analog threshold trigger occurs
when the signal attached to analog input channel 0 rises above 1.0 V (the fixed thresholdlevel).
For the DT9837A and DT9837B modules, the analog threshold trigger occurs when thesignal attached to analog input channel 0 rises above a user-specified threshold value. The
threshold level can be a value between 0.2 V and 9.8 V.
For the DT9837C module, the analog threshold trigger occurs when the signal attached to
one of the selected analog input channels rises above or falls below a user-specified
threshold value. Threshold level can be a value between ±10 V for a gain of 1 or ±1 V for again of 10.

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Specifying Input Triggers in Windows
When using DT-Open Layers in Windows, you can specify a start trigger source and areference trigger source when performing continuous scan operations.
Pre-trigger data acquisition starts when the start trigger event occurs. When the reference
trigger event occurs, pre-trigger data acquisition stops and post-trigger acquisition starts.
Post-trigger acquisition stops when the number of samples you specify for the post-trigger
scan count has been reached (see page 71 for more information).
You can specify any of the supported input trigger sources for the start trigger.
For the reference trigger, you can specify an analog threshold trigger only.
The reference trigger event occurs when the signal attached to a specified analog input
channel in the channel list rises above or falls below a user-specified threshold value. Using
software, specify the following parameters:• Reference trigger source – Specify a positive (low-to-high transition) threshold trigger if
you want to trigger when the signal rises above a threshold level, or a negative(high-to-low transition) threshold trigger if you want to trigger when the signal falls
below a threshold level.
• Threshold channel – Specify any one of the analog input channels that are included in thechannel list as the threshold input channel.
• Threshold level – Specify a value between ±10 V for a gain of 1 or ±1 V for a gain of 10 as
the threshold level.

Specifying Input Triggers in Linux or macOS
Reference triggers are not used in UL for Linux. Acquisition starts when the input trigger
occurs.
Users can monitor the data as it is being acquired to determine if a particular event (thresholdcrossing) has occurred.
Refer to Appendix D starting on page 145 for more information on UL for Linux.

Data Format and Transfer (Windows Only)
Note: This section applies to DT-Open Layers in Windows. If you are using Linux ormacOS, refer to the online help for UL for Linux (see https://github.com/mccdaq/uldaq) for
more information.

DT9837 Series modules use offset binary data encoding, where 000000 represents negative
full-scale, and FFFFFFh represents positive full-scale. When using DT-Open Layers in
Windows, use software to specify the data encoding as binary. The ADC outputs FFFFFFh forabove-range signals, and 000000 for below-range signals.

74Principles of Operation
Before you begin acquiring data, you must allocate buffers to hold the data. A Buffer Done
event is returned whenever a buffer is filled. This allows you to move and/or process the dataas needed.
We recommend that you allocate a minimum of two buffers for continuous analog input
operations. Data is written to multiple allocated input buffers continuously; when no more
empty buffers are available, the operation stops. The data is gap-free.

Note: The DT9837A and DT9837 C modules have an input FIFO of 2 kSamples; the DT9837B
has an input FIFO of 4 kSamples and the DT9837 does not use an input FIFO.

Error Conditions (Windows Only)
Note: This section applies to DT-Open Layers in Windows. If you are using Linux ormacOS, refer to the online help for UL for Linux (see https://github.com/mccdaq/uldaq) for
more information.

DT9837 Series modules report any overrun errors by sending an overrun event to theapplication program. This event indicates that data buffers are not being sent from the module
to the host fast enough, and the A/D converter ran out of buffers. To avoid this error, try one
or more of the following:• Reduce the clock rate of the A/D• Increase the size of the buffers• Increase the number of buffers• Close any other applications that are running• Run the program on a faster computer
If one of these error conditions occurs, the module stops acquiring and transferring data to thehost computer.

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Analog Output Features
This section describes the following features of analog output operations:• Analog output channels, described below• Output ranges and gains, described below• Output resolution, described on page 76• Output conversion mode, described on page 77• Output clocks, described on page 76• Output triggers, described on page 80• Data format and transfer, described on page 80• Error conditions, described on page 81

Analog Output Channels
The DT9837, DT9837A, and DT9837C modules support one analog output channel throughanalog output subsystem 0. Note that on the DT9837A module, you can read back the value ofthe analog output channel using software; refer to page 80 for more information.
The DT9837 and DT9837A modules provide a two-pole, 10 kHz Butterworth filter and theDT9837C provides a 40 kHz smoothing filter to prevent noise from interfering with the output
signal.
The analog output channel powers up to a value of 0 V ±10 mV.

Output Ranges and GainsThe DT9837 and DT9837A modules can output bipolar analog output signals in the range of±10 V, with a gain of 1.
The DT9837C module can output bipolar analog output signals in the range of ±3 V, with again of 1.

Output Resolution
The resolution of the analog output channel is fixed at 24-bits; you cannot specify the
resolution in software.

Output Clocks
The output clock on the DT9837, DT9837A, and DT9837C modules is derived from the USB
clock to produce the output clock frequency.

76

Principles of Operation
On the DT9837 module, the clock frequency is fixed at 46.875 kHz. On the DT9837A module,
you can program the clock frequency to value between 10 kHz and 52.734 kHz. On theDT9837C module, you can program the clock frequency to value between 10 kHz and
96.0 kHz.Use software to specify an internal clock source and to specify the clock frequency
for the analog output subsystem.
Internally, the value that you specify for the analog output clock frequency is multiplied by
512 to set the oscillator on the module. The maximum timebase for the DT9837 is 24 MHz; themaximum timebase for the DT9837A and DT9837C is 27 MHz.
Due to the group delay of the Delta-Sigma D/A converter, the DT9837 requires 34 clock
pulses, while the DT9837A and DT9837C modules require 29 clock pulses once the analog
output sample clock is started before the first D/A conversion is completed.

Output Conversion Modes (Windows Only)
Note: This section applies to DT-Open Layers in Windows. If you are using Linux ormacOS, refer to the online help for UL for Linux (see https://github.com/mccdaq/uldaq) for
more information on supported operation modes.

Using DT-Open Layers in Windows, the DT9837, DT9837A, and DT9837C modules support
single-value and waveform analog output operations. The DT9837A and DT9837C modules
also support continuous analog output operations. This section describes each of theseconversion modes.

Note: The DT9837A also provides the ability to read the value of the analog output channel
in the analog input data stream. Refer to page 80 for more information.

Single-Value Mode
Single-value mode is the simplest to use but offers the least flexibility and efficiency. Use
software to specify the analog output channel that you want to update, and the value to
output from that channel. The value is output from the specified channel immediately.
For a single-value operation, you cannot specify a clock source, trigger source, or buffer.
Single-value operations stop automatically when finished; you cannot stop a single-value
operation.

Note: On the DT9837 module, ensure that no analog input operations are running before
performing an analog output operation or an error will be reported.

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Waveform Generation Mode
Waveform generation mode is supported on the DT9837, DT9837A, and DT9837C modules. In
this mode, a waveform, which is specified in a single buffer, is output repetitively.
On the DT9837, allocate a buffer less than or equal to 8192 samples, and then fill the buffer
with the waveform that you want to output. On the DT9837A and DT9837C modules, you can
allocate a buffer of any size, and then fill the buffer with the waveform that you want to
output.
When it detects a software trigger, the host computer transfers the entire waveform pattern to
the 8 kSample output FIFO on the module, and the module starts writing output values to theanalog output channel at the specified clock rate. The module recycles the data, allowing you
to output the same pattern continuously without any further CPU or USB bus activity.
When it reaches the end of the FIFO, the module returns to the first location of the FIFO andcontinues outputting the data. This process continues indefinitely until you stop it.
To select waveform generation mode, use software to specify the following parameters:• Specify the data flow as Continuous• Specify WrapSingleBuffer as True to use a single buffer• Specify the clock source as internal and specify the clock frequency. Refer to page 76 formore information about the clock source and frequency.
• Specify a software trigger source, described in the next section

Note: On the DT9837, an error will be reported if you specify a buffer with greater than 8192
samples (the size of the output FIFO on the module).
If you want to output data from the analog output channel on the DT9837 module while
acquiring analog input data, ensure that you set up and start the analog output operation
before starting the analog input operation, or an error will be reported.

The DT9837, DT9837A, and DT9837C modules support the ability to mute the output voltage
to 0 V. Muting the output does not stop the analog output operation; instead, the analog
output voltage is reduced to 0 V over 1020 samples. When desired, you can unmute the output
voltage to its current level. Refer to your software documentation for more information on
muting and unmuting the output voltage.

Continuous Analog Output Operations
Continuous analog output operations are supported on the DT9837A and DT9837C modules
only. Use continuously paced analog output mode to continuously output buffered values tothe analog output channel at a specified clock frequency. The DT9837A and DT9837C support
the ability to start continuous analog output operations and continuous analog input
operations simultaneously.

78Principles of Operation
Use software to fill multiple output buffers with the values that you want to write to theanalog output channel. When it detects the specified trigger, the module starts writing thevalues from the output buffer to the analog output channel at the specified clock frequency.
The operation repeats continuously until either all the data is output from the buffers or you
stop the operation.

Note: Make sure that the host computer transfers data to the output channel list fast enoughso that the list does not empty completely; otherwise, an underrun error results.

To select continuously paced analog output mode, use software to specify the following
parameters:• Specify the data flow as Continuous• Specify WrapSingleBuffer as False to use multiple buffers• Specify the clock source as internal and specify the clock frequency. Refer to page 76 formore information about the clock source and frequency.
• Specify the trigger source as any of the supported trigger sources. Refer to page 80 for
more information about the supported trigger sources.
• To start the analog input and analog output operations simultaneously using the
DT-Open Layers for .NET Class Library, use the SimultaneousStart.AddSubsystem,
SimultaneousStart.PreStart, and SimultaneousStart.Start methods. Refer to the
documentation for the DT-Open Layers for .NET Class Library for more information.
We recommend that you allocate a minimum of two buffers for a continuously paced analog
output operation. Data is written from multiple output buffers continuously; when no more
buffers of data are available, the operation stops. The data is gap-free.
The DT9837, DT9837A, and DT9837C modules support the ability to mute the output voltage
to 0 V. Muting the output does not stop the analog output operation; instead, the analog
output voltage is reduced to 0 V over 1020 samples. When desired, you can use unmute theoutput voltage to its current level. Refer to your software documentation for more information
on muting and unmuting the output voltage.
To stop a continuously paced analog output operation, you can stop queuing buffers for the
analog output system, letting the module stop when it runs out of data, or you can perform
either an orderly stop or an abrupt stop using software. In an orderly stop, the module
finishes outputting the specified number of samples, and then stops; all subsequent triggers
are ignored. In an abrupt stop, the module stops outputting samples immediately; allsubsequent triggers are ignored.

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Reading Back the Analog Output Value (DT9837A Only)
On the DT9837A module only, you can read back the value of the analog output channel in
the analog input stream.
If you are using DT-Open Layers in Windows, specify channel 7 in the analog input channel
list to read back the value of the analog output channel. When the analog input operation isstarted, the value of the analog output channel is returned in the analog input data stream.
The software automatically synchronizes the value of the analog output channel with theanalog input measurements, so that all measurements are correlated in time.
If you are using UL for Linux, refer to page 152 for more information on reading the analog
output value.

Output Trigger
The DT9837, DT9837A, and DT9837C modules support the following trigger sources forstarting analog output operations:• Software trigger – A software trigger event occurs when you start the analog output
operation (the computer issues a write to the module to begin conversions) using
software.
• External digital (TTL) trigger – This trigger source is supported on the DT9837A andDT9837C modules. An external digital (TTL) trigger event occurs when the module
detects a rising-edge transition on the signal connected to the Ext Trig connector on themodule.
• Analog threshold trigger – This trigger source is supported on the DT9837A andDT9837C modules.
For the DT9837A module, an analog threshold trigger event occurs when the signal
attached to analog input channel 0 rises above a user-specified threshold value. Using
software, specify the trigger source as a positive threshold trigger, the threshold trigger
channel as analog input channel 0, and the threshold level as a value between 0.2 V and
9.8 V.
For the DT9837C module, the analog threshold trigger event occurs when the signal
attached to a specified analog input channel rises above a user-specified threshold value.
The threshold level can be a value between ±10 V for a gain of 1 or ±1 V for a gain of 10.

Data Format and Transfer (Windows Only)
Data from the host computer must use offset binary data encoding for analog output signals,
where 000000 represents 10 V, and FFFFFFh represents +10 V.
When using DT-Open Layers in Windows, specify the data encoding as binary.

80Principles of Operation

Error Conditions (Windows Only)
The DT9837, DT9837A, and DT9837C modules report any underrun errors by sending an
underrun event to the application. This event indicates that the data buffers are not being sentfrom the host to the module fast enough, and the D/A converter ran out of data. To avoid thiserror, try one or more of the following:• Reduce the clock rate of the analog output operation• For the DT9837, ensure that you allocate a single buffer with 8192 or fewer samples• Close any other applications that are running• Run the program on a faster computer81

Chapter 5

Tachometer Input Features
You can connect a tachometer signal with a range of ±30 V to the DT9837, DT9837A, andDT9837B modules. (The DT9837C does not support a tachometer input.) On the DT9837, thissignal has a maximum frequency of 380 kHz and a minimum pulse width of 1.3 s. On theDT9837A and DT9837B modules, this signal has a maximum frequency of 1 MHz and aminimum pulse width of 0.4 s. The threshold voltage is fixed at +2 V with 0.5 V of hysteresis.
You can measure the frequency or period of the tachometer input signal using tachometercounter 0. On the DT9837A and DT9837B modules, you can also measure the phase of thetachometer input signal in relation to the A/D sample using tachometer counter 1. These
measurements are described in more detail in the following subsections.

Frequency or Period Measurements – Tachometer Counter 0
Use frequency or period measurements to calculate the rotation speed for high-level (±30 V)
tachometer input signals. An internal 12 MHz counter (tachometer counter 0) is used for themeasurement, yielding a resolution of 83 ns (1/12 MHz).
You can read the number of counts between two consecutive starting edges of the tachometer
input signal. On the DT9837A and DT9837B, you can specify the following parameters fortachometer counter 0 using software:• The starting edge of the tachometer input signal to use for the measurement: rising edgeor falling edge. On the DT9837 module, the starting edge is always the rising edge.
• The value read between measurements: either zero or the previous measurement value.
On the DT9837 module, this value is always the previous measurement value.
• A flag (called Stale) indicating whether or not the data is new. If the Stale flag is set as
Used, the most significant bit (MSB) of the value is set to 0 to indicate new data; reading
the value before the measurement is complete returns an MSB of 1. If the Stale flag is set to
Not Used, the MSB is always set to 0.
On the DT9837 module, the MSB is always 0 (Not Used).
When the operation is started, the internal 12 MHz counter starts incrementing when it
detects the first starting edge of the tachometer input and stops incrementing when it detects
the next starting edge of the tachometer input. When the measurement is complete, thecounter/timer remains idle until it is read. On the next read, either 0 or the current value ofthe tachometer input (from the previous measurement operation) is returned depending on
the module and its settings, described above, and the next operation is started automatically.

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Principles of Operation
Using the count that is returned from the tachometer input, you can determine the following:• Frequency of a signal pulse (the number of periods per second). You can calculate thefrequency as follows: Frequency = 12 MHz/(Number of counts – 1)
where 12 MHz is the internal counter/timer clock frequency
For example, if the count is 21, the measured frequency is 600 kHz (12 MHz/20).
• Period of a signal pulse. You can calculate the period as follows: Period = 1/Frequency
 Period = (Number of counts – 1)/12 MHz
where 12 MHz is the internal counter/timer clock frequency

Reading Tachometer Counter 0 Using Windows
In Windows, you can read tachometer counter 0 by specifying channel 4 in the analog input
channel list. You can specify the parameters for tachometer counter 0 by using the Open
Layers Control Panel applet, described on page 36, by using software commands, or by
writing to the registers of the module, as described in Appendix C starting on page 135.
The software automatically synchronizes the value of the tachometer input with the analog
input measurements, so that all measurements are correlated in time.
The tachometer input is treated like any other channel in the analog input channel list;
therefore, all the triggering and conversion modes supported for analog input channels aresupported for the tachometer input.
When you read the value of the tachometer input as part of the analog input data stream, you
might see results similar to the following (note that this assumes that the previous
measurement value is returned between new measurement values):
Table 2: An Example of Reading the Tachometer Input as Part of theAnalog Input Data StreamTime

A/D Value

Tachometer
Input Value

10

5002

0

Operation started, but is not complete

20

5004

0

Operation not complete

30

5003

0

Operation not complete

40

5002

12373

Operation complete

50

5000

12373

Next operation started, but is not complete

60

5002

12373

Operation not complete

70

5004

12373

Operation not complete

80

5003

14503

Operation complete

90

5002

14503

Next operation started, but is not complete

Status of Operation

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Reading Tachometer 0 Using in Linux or macOSIf you are using UL for Linux, you can read and configure tachometer counter 0 through thecounter subsystem. Refer to page 147 for more information on reading and configuring
tachometer counter 0.

Phase Measurements – Tachometer Counter 1
On the DT9837A and DT9837B modules, you can measure the phase of the tachometer input
in relation to the A/D sample by reading tachometer counter 1.
An internal 48 MHz clock (with 21 ns resolution) is used to calculate the measurement, whichallows you to precisely correlate tachometer measurements with the analog input data.
Using software, you can specify the following parameters for tachometer counter 1:• The signal that starts the measurement: A/D sample, rising edge of the tachometer input
signal, or falling edge of the tachometer input signal• The signal that stops the measurement: A/D sample, rising edge of the tachometer input
signal, or falling edge of the tachometer input signal
Note: Note that if you choose to start the measurement using the A/D sample, choose atachometer edge to stop the measurement. Likewise, if you choose to stop themeasurement using the A/D sample, choose a tachometer edge to start the measurement.
• The value of the Self-Clear flag, which determines the value that is read between
measurements (either 0 or the previous measurement value)
If you are using DT-Open Layers in Windows, specify channel 5 in the analog input channel
list to read the value of tachometer counter 1. You can specify the parameters for tachometercounter 1 using the Open Layers Control Panel applet, described on page 36, or by writing to
the registers of the module, as described in Appendix C starting on page 135:
If you are using UL for Linux, refer to page 150 for more information on specifying tachometercounter 1 and its parameters.

84Principles of Operation

Gate Input Features
The DT9837A-OEM module provides a 4-pin gate input connector for connecting a TTL gate
input signal; see page 133 for connector pin assignments. The DT9837B module provides a
BNC connector for connecting a gate input signal.
You can read the value of gate counter 2 to measure the phase between the following signals:• Completion of the A/D sample to the rising or falling edge of the gate input signal• Rising or falling edge of the gate input signal to the completion of the A/D sample
You can also determine the pulse width of the gate signal by measuring between the Rising or
falling edge of the gate input signal to the next rising or falling edge of the gate input signal.
An internal 48 MHz clock (with 21 ns resolution) is used to calculate the measurements, whichallows you to precisely correlate analog input data with measurements from the gate input
signal.
You can specify the following parameters for gate counter 2 using software:• The signal that starts the measurement: A/D sample, gate rising edge, or gate falling edge
• The signal that stops the measurement: A/D sample, gate rising edge, or gate falling edge
Note: Note that if you choose to start the measurement using the A/D sample, choose agate input edge to stop the measurement. Likewise, if you choose to stop themeasurement using the A/D sample, choose a gate input edge to start the measurement.
If you choose the start and stop the measurement using the same gate edge, be aware thatthe stopping edge does not restart the measurement; the next starting edge will start thenext measurement.
• The value of the Self-Clear flag, which determines the value that is read between
measurements (either 0 or the previous measurement value)
If you are using DT-Open Layers in Windows, specify channel 6 in the analog input channel
list to read the value of gate counter 2. You can specify the parameters for gate counter 2 using
the Open Layers Control Panel applet, described on page 36, or by writing to the registers ofthe module, as described in Appendix C starting on page 135:
If you are using UL for Linux, refer to page 151 for more information on specifying gate
counter 2 and its parameters.

85

Chapter 5

Triggering Acquisition on Multiple Modules
Note: For DT9837A, DT9837B, and DT9837C modules, you can synchronize acquisition on
multiple modules using the RJ45 (LVDS) synchronization connector, described on page 87.

The internal clock on the DT9837, DT9837A, and DT9837C modules when the synchronization
mode is none (see page 87), is derived from the USB clock and provides the timing for both theanalog input and analog output subsystems on the module.
You can start acquisition on multiple modules by connecting all modules to a shared external
trigger input, as shown in Figure 24. When triggered, the modules start acquiring data at thesame time.
Using this connection scheme, the measurements of one module may not be synchronouswith the measurements of another module due to logic delays in the clocking and USB
circuitry.

Host PC

Device Under
Test

External
TriggerUSB
Port 1
InputsDT9837
Series #1

InputsDT9837
Series #2

USB
Port 2

USB
Port n.
.
.
InputsDT9837
Series #n

Figure 24: Triggering Multiple Modules Using an External Trigger Source86Principles of Operation

Synchronizing Acquisition on Multiple DT9837A,
DT9837B, or DT9837C Modules
DT9837A, DT9837B, and DT9837C modules provide an RJ45 (LVDS) synchronization
connector that you can use to connect and synchronize multiple DT9837A, DT9837B, orDT9837C modules. In this scheme, one module is the master and the other modules are theslaves.

Notes: When using the master/slave configuration, you can use DT9837A and DT9837B
modules together, however, the maximum sampling rate is limited by the slowest module(52.7 kHz, in this case). If you are using DT9837C modules in a master/slave configuration, it
is recommended that you do not connect any other module type except the DT9837C.
You cannot use the Ext Trig connector on slave modules.
For the DT9837A and DT9837B modules, you cannot use an analog threshold trigger for theslave modules.
For DT9837C modules, if you are using an analog threshold trigger for the master DT9837C
module, you must configure slave DT9837C modules to use an analog threshold trigger as
well.

In Windows, you specify the synchronization mode of the RJ45 connector as master, slave, ornone. When configured as a master, the RJ45 synchronization connector outputs trigger andclock signals. When configured as a slave, the RJ45 connector accepts trigger and clock signals
from the master. When synchronization is none, the DT9837A, DT9837B, or DT9837C module
uses the USB clock instead of the RJ45 synchronization connector. The synchronization moderemains set until changed or until the application exits.
If you are using Linux or macOS, refer to page 153 for information on specifying thesynchronization mode.
You can connect multiple modules in one of two ways. Figure 25 shows how to connect amaximum of two DT9837A, DT9837B, or DT9837C modules by daisy chaining them together
through the RJ45 connector. Figure 26 shows how to connect a maximum of four DT9837A,
DT9837B, or DT9837C modules by using an RJ45 distribution panel, such as the EP386, where
the panel contains four RJ45 connectors that are wired in parallel.

Note: You must have revision H or later of the DT9837A module or revision F or later of theDT9837A-OEM module to be able to attach four modules together. You can identify therevision of your module by looking at the serial number label on your module.
If you have revision G or earlier of the DT9837A or revision E or earlier of theDT9837A-OEM, you can attach a maximum of two modules together.

87

Chapter 5

Host PC

USB
Port 1

DeviceUnder Test

External
Trigger

InputsDT9837A,
DT9837B, orDT9837C
MasterUSB
Port 2USB

RJ45 (LVDS)

InputsUSB

DT9837A,
DT9837B, orDT9837C
Slave

Figure 25: Synchronizing Two DT9837A, DT9837BB, or DT9837C Modules by Daisy Chaining the
RJ45 Connectors (Shown Using an External Trigger)

Host PC
USB
Port 1

USB
Port 2

USB
Port 3

USB
Port 4

DeviceUnder Test

InputsExternal
Trigger
Inputs

Inputs

InputsDT9837A,
DT9837B, orDT9837C
MasterUSB

DT9837A,
DT9837B, orDT9837C
Slave

USB

DT9837A,
DT9837B, orDT9837C
Slave

USB

DT9837A,
DT9837B, orDT9837C
Slave

EP386
RJ45 Distribution
Panel(connectors wired

RJ45 (LVDS)

RJ45 (LVDS)

RJ45 (LVDS)USB
RJ45 (LVDS)* The RJ45 cables must be less than 1 foot in length. For
minimum clock skew, the master module must be less than 4
inches away from the RJ45 distribution panel.

Figure 26: Synchronizing Four DT9837A, DT9837B, or DT9837C Modules Using the EP386
RJ45 Distribution Panel (Shown Using an External Trigger)88Principles of Operation
For Windows only, when synchronizing multiple modules, you must start the slave modules
before starting the master module. When the master module is triggered (using any of the
supported trigger sources), both the master and the slave modules start acquiring data at thesame time (within one A/D conversion of the clock). Note that you can set the clock rate to be
the same or different on each module.

Note: (Windows only) It is important that you start the slave modules first, followed by themaster module so that the slave receives the appropriate clock and trigger signals from themaster.
If you start the master module before the slaves, the slaves never start; you will see a delay of
approximately 20 seconds if you try to stop or abort the analog input operation on a slave
module that is waiting for a trigger.

When you stop the master module, the slaves continue to run and return data until you stop
the analog input subsystem on the slave modules. Be sure to stop the analog input subsystems
on all DT9837A, DT9837B, or DT9837C modules before disconnecting the cable from the RJ45
connectors.

89

Chapter 5906
Supported Device Driver Capabilities(Windows Only)
Data Flow and Operation Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Buffering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Triggered Scan Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Data Encoding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Current and Resistance Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Thermocouple, RTD, and Thermistor Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
IEPE Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Bridge and Strain Gage Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Start Triggers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Reference Triggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Clocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Counter/Timers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Tachometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

91

Chapter 6

Note: This chapter applies to programming in DT-Open Layers in Windows. For
information on programming in Linux, refer to Appendix D starting on page 145.

Windows DT9837 Series Device Drivers provide support for the analog input (A/D) andanalog output (D/A) subsystems. For information on how to configure the device drivers,
refer to page 36.
Table 3: DT9837 Series Subsystems
DT9837 Series Modules
Total Subsystems on Module

A/D
1

D/A
1a or 2b 0

DIN

DOUT
0

C/T
0

TACH QUAD
0c0a. The DT9837 supports D/A subsystem 0 to access the capabilities of the analog output subsystem.
The DT9837B supports D/A subsystem 0 to program the threshold value for the analog threshold
trigger, but the threshold level can also be programmed directly through the analog input
subsystem using software.
b. The DT9837A supports two D/A subsystem (0 and 1). Use D/A subsystem 0 to access thecapabilities of the analog output subsystem. D/A subsystem 1 is available to program thethreshold value for the analog threshold trigger, but the threshold level can also be programmed
directly through the analog input subsystem using software.
c. The DT9837 supports one tachometer input for measuring frequency or period. The DT9837A andDT9837B support one tachometer input for measuring frequency or period and a gate input formeasuring phase. The DT9837C does not support a tachometer input.
You cannot use the DT-Open Layers for .NET Class Library to configure the tachometer or gate
input on the DT9837 Series modules. Instead, use the Open Layers Control Panel applet,
described on page 36, or write to the registers of the module, described on page 135, to configure
the tachometer and/or gate input parameters.
You read the value of the tachometer and gate input signals through the A/D subsystem.

The tables in this chapter summarize the features available for use with the DT-Open Layers
for .NET Class Library and the DT9837 Series modules. The DT-Open Layers for .NET Class
Library provides properties that return support information for specified subsystemcapabilities.
The first row in each table lists the subsystem types. The first column in each table lists all
possible subsystem capabilities. A description of each capability is followed by the property
used to describe that capability in the DT-Open Layers for .NET Class Library.

Note: The following tables include the capabilities that can be queried. However, some
capabilities may not be supported by your device. Blank fields represent unsupported
options.

For more information, refer to the description of these properties in the DT-Open Layers for.NET Class Library online help or DT-Open Layers for .NET Class Library User’s Manual.

92Supported Device Driver Capabilities (Windows Only)

Data Flow and Operation Options
Table 4: Data Flow and Operation Options
DT9837 Series Modules
Single-Value Operation Support
SupportsSingleValue

D/Aa

A/D
Yes

Yesb

Yes

Yesc

DIN

DOUT

C/T

TACH

QUAD

Simultaneous Single-Value Output Operations
SupportsSetSingleValues
Continuous Operation Support
SupportsContinuous
Continuous Operation until Trigger
SupportsContinuousPreTrigger
Continuous Operation before & after Trigger
SupportsContinuousPrePostTrigger
Waveform Operations Using FIFO Only
SupportsWaveformModeOnly
Simultaneous Start List Support
SupportsSimultaneousStart

Yesd
Yese

Yese

Supports Programmable Synchronization Modes
SupportsSynchronization
Yes
Synchronization Modes
SynchronizationMode

None, Master,
Slave

Interrupt Support
SupportsInterruptOnChange
FIFO Size, in samples
FifoSize
Muting and Unmuting the Output Voltage
SupportsMute

2 kSamples or
4 kSamplesf 8 kSamplesg
Yes

Auto-Calibrate Support
SupportsAutoCalibrate
a. The D/A subsystem is not supported by the DT9837B module.
b. To perform a single value analog output operation, ensure that no analog input operations are running or an error will bereported.
c. For the DT9837, if you want to output data from the analog output channel while acquiring analog input data, ensure that you
set up and start the analog output operation before starting the analog input operation, or an error will be reported.
d. The DT9837A and DT9837C modules support continuous analog output operations in addition to waveform mode.
e. The DT9837A and DT9837C modules support the ability to start continuous A/D and continuous D/A operations
simultaneously.
f. The DT9837A and DT9837 C modules have an input FIFO of 2 kSamples; the DT9837B has an input FIFO of 4 kSamples; andthe DT9837 does not use an input FIFO.
g. The DT9837B does not have an output FIFO. The output FIFO on the DT9837, DT9837A, and DT9837C is 8 kSamples.

93

Chapter 6

Buffering
Table 5: Buffering Options
DT9837 Series Modules
Buffer Support
SupportsBuffering

A/D
Yes

DIN

DOUT

C/T

TACH QUAD

C/T

TACH QUAD

YesSingle Buffer Wrap Mode Support
SupportsWrapSingle
Inprocess Buffer Flush Support
SupportsInProcessFlush

D/Aa

Yes
Yes

a. The D/A subsystem is not supported by the DT9837B module.

Triggered Scan Mode
Table 6: Triggered Scan Mode Options
DT9837 Series Modules

A/D

D/A

DIN

DOUT

Triggered Scan Support
SupportsTriggeredScan
Maximum Number of CGL Scans per Trigger
MaxMultiScanCount
1

0

0

0

0

0

Maximum Retrigger Frequency
MaxRetriggerFreq

0

0

0

0

0

0

Minimum Retrigger Frequency
MinRetriggerFreq

0

0

0

0

0

0

Data Encoding
Table 7: Data Encoding Options
DT9837 Series Modules
Binary Encoding Support
SupportsBinaryEncoding

A/D
Yes

D/Aa

DIN

Yes

Twos Complement Support
SupportsTwosCompEncoding
Returns Floating-Point Values
ReturnsFloats
a. The D/A subsystem is not supported by the DT9837B module.

94

DOUT

C/T

TACH QUAD

Supported Device Driver Capabilities (Windows Only)

Channels
Table 8: Channel Options
DT9837 Series Modules

D/Aa

A/D

Number of Channels
NumberOfChannels

4b, 5c, 7d, or 8e

1

SE Support
SupportsSingleEnded

Yes

Yes

SE Channels
MaxSingleEndedChannels

4

DI Channels
MaxDifferentialChannels

DIN

DOUT

C/T

TACH QUAD

0

0

0

0

1

0

0

0

0

0

0

0

0

Maximum Channel-Gain List Depth
CGLDepth

4b, 5c, 7d, or 8e

1

0

0

0

0

Simultaneous Sample-and-Hold Support
SupportsSimultaneousSampleHold

Yes0

DI Support
SupportsDifferential

Channel-List Inhibit
SupportsChannelListInhibit
Support MultiSensor Inputs
SupportsMultiSensor
Bias Return Termination Resistor Support
SupportsInputTerminationa. The D/A subsystem is not supported by the DT9837B module.
b. On the DT9837C, channels 0 to 3 correspond to the analog input channels.
c. On the DT9837, channels 0 to 3 correspond to the analog input channels; channel 4 corresponds to tachometercounter 0.
d. On the DT9837B, channels 0 to 3 correspond to the analog input channels; channel 4 corresponds to tachometercounter 0; channel 5 corresponds to tachometer counter 1, and channel 6 corresponds to gate counter 2.
e. On the DT9837A, channels 0 to 3 correspond to the analog input channels; channel 4 corresponds to tachometercounter 0; channel 5 corresponds to tachometer counter 1, channel 6 corresponds to gate counter 2 on theDT9837A-OEM module, and channel 7 corresponds to the analog output readback channel.

Gain
Table 9: Gain Options
DT9837 Series Modules

D/Aa

A/D

Programmable Gain Support
SupportsProgrammableGain

Yes

Number of Gains
NumberOfSupportedGains

2

1

Gains Available
SupportedGains

1 and 10

1

DIN

0

DOUT

0

C/T

0

TACH QUAD

0a. The D/A subsystem is not supported by the DT9837B module.

95Chapter 6

RangesTable 10: Range Options
DT9837 Series Modules

D/Aa

A/D

DIN

Number of Voltage Ranges
NumberOfRanges

11

Available Ranges
SupportedVoltageRanges±10 Vb

±10 V or ±3 Vc

0

DOUT
0

C/T

TACH QUAD

00a. The D/A subsystem is not supported by the DT9837B module.
b. By applying a gain of 1, the effective input range is ±10 V. By applying a gain of 10, the effective input range is±1 V.
c. The DT9837and DT9837A support an output voltage range of ±10 V; the DT9837C supports an output voltage
range of ±3 V.

Resolution
Table 11: Resolution Options
DT9837 Series Modules

D/Aa

A/D

DIN

DOUT

C/T

TACH QUAD

Software Programmable Resolution
SupportsSoftwareResolution
Number of Resolutions
NumberOfResolutions

1

1

0

0

0

0

Available Resolutions
SupportedResolutions

24

24

0

0

0

0

a. The D/A subsystem is not supported by the DT9837B module.

Current and Resistance Support
Table 12: Current and Resistance Support Options
DT9837 Series
Current Support
SupportsCurrent
Current Output Support
SupportsCurrentOutput
Resistance Support
SupportsResistance
Software Programmable External Excitation Current Source
for Resistance
SupportsExternalExcitationCurrentSrc
Software Programmable Internal Excitation Current Source
SupportsInternalExcitationCurrentSrc
Available Excitation Current Source Values
SupportedExcitationCurrentValues

96

A/D

D/A

DIN

DOUT

C/T

TACH QUAD

Supported Device Driver Capabilities (Windows Only)

Thermocouple, RTD, and Thermistor Support
Table 13: Thermocouple, RTD, and Thermistor Support Options
DT9837 Series

A/D

D/A

DIN

DOUT

C/T

TACH

QUAD

Thermocouple Support
SupportsThernocouple
RTD Support
SupportsRTD
Thermistor Support
SupportsThermistor
Voltage Converted to Temperature
SupportsTemperatureDataInStream
Supported Thermocouple Types
ThermocoupleType
Supports CJC Source Internally in Hardware
SupportsCjcSourceInternal
Supports CJC Channel
SupportsCjcSourceChannel
Available CJC Channels
CjcChannel
Supports Interleaved CJC Values in Data Stream
SupportsInterleavedCjcTemperaturesInStream
Supported RTD Types
RTDType
RTD R0 Coefficient
RtdR0
Supports Data Filters
SupportsTemperatureFilters
Temperature Filter Types
TemperatureFilterType97

Chapter 6

IEPE Support
Table 14: IEPE Support Options
DT9837 Series

A/D

IEPE Support
SupportsIEPE

Yes

Software Programmable AC Coupling
SupportsACCoupling

Yes

Software Programmable DC Coupling
SupportsDCCoupling

Yes

D/A

DIN

DOUT

C/T

TACH QUAD

Software Programmable External Excitation Current Source
SupportsExternalExcitationCurrentSrc
Software Programmable Internal Excitation Current Source
SupportsInternalExcitationCurrentSrc

Yes

Available Excitation Current Source Values
SupportedExcitationCurrentValues.004 Aor.002 Aa

a. The DT9837, DT9837A, and DT9837B support an internal excitation current of 4 mA, while the DT9837C supports aninternal excitation current source of 2 mA.

Bridge and Strain Gage Support
Table 15: Bridge and Strain Gage Support Options
DT9837 Series
Bridge Support
SupportsBridge
Supported Bridge Configurations
BridgeConfiguration
Strain Gage Support
SupportsStrainGage
Supported Strain Gage Bridge Configurations
StrainGageBridgeConfiguration
External Excitation Voltage
SupportsExternalExcitationVoltage
Internal Excitation Voltage
SupportsInternalExcitationVoltage
Shunt Calibration
SupportsShuntCalibration
Voltage Excitation Per Channel
SupportedPerChannelVoltageExcitation
Minimum Excitation Voltage
MinExcitationVoltage
Maximum Excitation Voltage
MaxExcitationVoltage

98

A/D

D/A

DIN

DOUT

C/T

TACH QUAD

Supported Device Driver Capabilities (Windows Only)

Start Triggers
Table 16: Start Trigger Options
DT9837 Series

A/D

D/A

Software Trigger Support
SupportsSoftwareTrigger

Yes

Yesa

External Positive TTL Trigger Support
SupportsPosExternalTTLTrigger

Yes

Yesb

Positive Threshold Trigger Support
SupportsPosThresholdTrigger

Yesc

Yesd

Negative Threshold Trigger Support
SupportsNegThresholdTrigger

Yese

DIN

DOUT

C/T

TACH QUAD

External Negative TTL Trigger Support
SupportsNegExternalTTLTrigger
External Positive TTL Trigger Support forSingle-Value Operations
SupportsSvPosExternalTTLTrigger
External Negative TTL Trigger Support
for Single-Value Operations
SupportsSvNegExternalTTLTrigger

Digital Event Trigger Support
SupportsDigitalEventTrigger
Threshold Trigger Channel
SupportedThresholdTriggerChannel

0 or 0 to 3c

0 or 0 to 3f

a. This trigger is option is not supported for the DT9837B module.
b. On the DT9837A and DT9837C, you can use the external trigger to trigger D/A subsystem 0.
c. If you choose a threshold trigger for the start trigger on the DT9837, the threshold level is fixed at 1.0 V and thethreshold channel is analog input channel 0.
If you choose a threshold trigger for the start trigger on the DT9837A or DT9837B, you can program thethreshold level from 0.2 V to 9.8 V and the threshold channel is analog input channel 0.
If you choose a threshold trigger for the start trigger on the DT9837C module, you can program the thresholdlevel as a value between ±10 V for a gain of 1 or ±1 V for a gain of 10, and any of the supported analog input
channels can be used as the threshold channel.
d. On the DT9837A and DT9837C, you can use the analog threshold trigger to trigger D/A subsystem 0.
e. The DT9837C supports a negative threshold trigger.
f. On the DT9837A, you can use analog input channel 0 as the analog threshold trigger channel to start analog
output operations. On the DT9837C, you can use any of the analog input channels as the threshold trigger
channel to start analog output operations.

99

Chapter 6

Reference Triggers
Table 17: Reference Trigger Options
DT9837 Series

A/D

D/A

DIN

DOUT

C/T

TACH QUAD

External Positive TTL Trigger Support
SupportsPosExternalTTLTrigger
External Negative TTL Trigger Support
SupportsNegExternalTTLTrigger
Positive Threshold Trigger Support
SupportsPosThresholdTrigger

Yesa

Negative Threshold Trigger Support
SupportsNegThresholdTrigger

Yesa

Digital Event Trigger Support
SupportsDigitalEventTrigger
Sync Bus Support
SupportsSyncBusTrigger
Analog Input Channels Supported for the Threshold Trigger
SupportedThresholdTriggerChannels

0 to 3Post-Trigger Scan Count Support
SupportsPostTriggerScanCountYesb

a. If you choose a threshold trigger as a reference trigger on any of the DT9837 Series modules, you can program the thresholdlevel as a value between ±10 V for a gain of 1 or ±1 V for a gain of 10, and any of the supported analog input channels can beused as the threshold channel.
b. If you use a reference trigger, you can specify how many post-trigger samples to acquire after the reference trigger byspecifying the post-trigger scan count in software.

100Supported Device Driver Capabilities (Windows Only)

ClocksTable 18: Clock Options
DT9837 Series
Internal Clock Support
SupportsInternalClock

D/Aa

A/D
Yes

DIN

DOUT

C/T

TACH

QUAD

Yes

External Clock Support
SupportsExternalClock
Simultaneous Input/Output on a Single
Clock Signal
SupportsSimultaneousClocking
Yes
Base Clock Frequency
BaseClockFrequency

27 MHz24 MHz or 27
MHzb

0

0

Maximum Clock Divider
MaxExtClockDivider

1.0

1.0

1

1

1

1

Minimum Clock Divider
MinExtClockDivider

1.0

1.0

1

1

1

1

Maximum Frequency
MaxFrequency

52.734 kHz,105.469 kHzc

46.875 kHz,52.734 kHz, or
96 kHzd

0

0

0

0

Minimum Frequency
MinFrequency

195.3 Hz46.875 kHz or
10 kHzd

0

0

0

0

a. The D/A subsystem is not supported by the DT9837B module.
b. The base clock for the D/A subsystem on the DT9837 is fixed at 24 MHz; the base clock for the D/A subsystem on theDT9837A and DT9837C has a maximum frequency of 27 MHz.
c. The DT9837 and DT9837A support a maximum sampling frequency of 52.734 kHz; the DT9837B and DT9837C support amaximum sampling frequency of 105.469 kHz.
d. The DT9837 supports a fixed clock frequency of 46.875 kHz for D/A subsystem 0; the DT9837A supports programmableclock frequencies from 10 kHz to 52.734 kHz for D/A subsystem 0; and the DT9837C supports programmable clock
frequencies from 10 kHz to 96 kHz for D/A subsystem 0101

Chapter 6Counter/Timers
Table 19: Counter/Timer Options
DT9837 Series
Cascading Support
SupportsCascading
Event Count Mode Support
SupportsCount
Generate Rate Mode Support
SupportsRateGenerate
One-Shot Mode Support
SupportsOneShot
Repetitive One-Shot Mode Support
SupportsOneShotRepeat
Up/Down Counting Mode Support
SupportsUpDown
Edge-to-Edge Measurement Mode Support
SupportsMeasureContinuous Edge-to-Edge Measurement Mode Support
SupportsContinuousMeasureHigh to Low Output Pulse Support
SupportsHighToLowPulse
Low to High Output Pulse Support
SupportsLowToHighPulse
Variable Pulse Width Support
SupportsVariablePulseWidth
None (internal) Gate Type Support
SupportsGateNone
High Level Gate Type Support
SupportsGateHighLevel
Low Level Gate Type Support
SupportsGateLowLevel
High Edge Gate Type Support
SupportsGateHighEdge
Low Edge Gate Type Support
SupportsGateLowEdge
Level Change Gate Type Support
SupportsGateLevel
Clock-Falling Edge Type
SupportsClockFalling
Clock-Rising Edge Type
SupportsClockRisingGate-Falling Edge Type
SupportsGateFalling
Gate-Rising Edge Type
SupportsGateRisingInterrupt-Driven Operations
SupportsInterrupt

102

A/D

D/A

DIN

DOUT

C/T

TACH QUAD

Supported Device Driver Capabilities (Windows Only)

Tachometer
Table 20: Tachometer Options
DT9837 Series

A/D

D/A

DIN

DOUT

C/T

TACH QUAD

Tachometer Falling Edges
SupportsFallingEdge

Yesa

Tachometer Rising Edges
SupportsRisingEdge

Yesa

Tachometer Stale Data Flag
SupportsStaleDataFlag

Yesb

a. On the DT9837 module, the starting edge is always rising; on the DT9837A and DT9837B modules, the starting edge is
programmable (either rising or falling). For the DT9837A and DT9837B, you specify the edge using the Open Layers
Control Panel applet, described on page 36, or by writing to the registers of the module, described on page 135; youcannot use the DT-Open Layers for .NET Class Library to configure these settings.
b. The Stale Data flag can be 0 or 1 on the DT9837A and DT9837B; the Stale Data flag is always 0 on the DT9837. For theDT9837A and DT9837B, you specify whether to use the Stale Data Flag using the Open Layers Control Panel applet,
described on page 36, or by writing to the registers of the module, described on page 135; you cannot use the DT-Open
Layers for .NET Class Library to configure these settings.

103

Chapter 6

104

7
Troubleshooting
General Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Technical Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
If Your Module Needs Factory Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

105

Chapter 7

General Checklist
Should you experience problems using a DT9837 Series module, do the following:
1. Read all the documentation provided for your product, including any “Read This First”
information to your manual.
2. Check that your system meets the requirements stated on page 32.
3. Check that you have installed your hardware properly using the instructions in Chapter
2.
4. If you are using Windows, check that you have installed and configured the device driverfor your module using the instructions in Chapter 2.
5. Check that you have wired your signals properly using the instructions in Chapter 3.
6. Search the Knowledgebase in the Support section of the web site (at www.mccdaq.com)
for an answer to your problem.
If you still experience problems, try using the information in Table 21 to isolate and solve theproblem. If you cannot identify the problem, refer to page 108.
Table 21: Troubleshooting Problems
Symptom
Module is notrecognized

Possible Cause
You plugged the module into yourcomputer before installing the device
driver.

Possible Solution
In Windows, go to Control Panel > System >Hardware > Device Manager, uninstall any
unknown devices (showing a yellow questionmark). Then, run the setup program on yourOMNI CD to install the USB device drivers, andreconnect your USB module to the computer.
In Linux or macOS, install UL for Linux (seeAppendix D), reconnect your USB module tothe computer, and run your application.

Module does not
respond

The module configuration is incorrect.

In Windows, check the configuration of yourdevice driver; see the instructions in Chapter 2.
In Linux or macOS, check the settings in yourprogram. Refer to Appendix D for more
information.

The module is damaged.

106

Contact Data Translation for technical support;
refer to page 108.

Troubleshooting
Table 21: Troubleshooting Problems (cont.)
SymptomIntermittent
operation

Device failure
error reported

Data appears to
be invalid

USB 2.0 is notrecognized

Possible Cause

Possible Solution

Loose connections or vibrations exist.

Check your wiring and tighten any loose
connections or cushion vibration sources; see
the instructions in Chapter 3.

The module is overheating.

Check environmental and ambient
temperature; consult the module’s
specifications on page 127 of this manual andthe documentation provided by your computer
manufacturer for more information.

Electrical noise exists.

Check your wiring and either provide bettershielding or reroute unshielded wiring; see theinstructions in Chapter 3.

The DT9837 Series module cannot
communicate with the Microsoft bus driveror a problem with the bus driver exists.

Check your cabling and wiring and tighten any
loose connections; see the instructions in
Chapter 3.

The DT9837 Series module was removed
while an operation was being performed.

Ensure that your module is properly connected;
see the instructions in Chapter 2.

An open connection exists.

Check your wiring and fix any open
connections; see the instructions in Chapter 3.

A transducer is not connected to thechannel being read.

Check the transducer connections; see theinstructions in Chapter 3.

The module is set up for differential inputs
while the transducers are wired as
single-ended inputs or vice versa.

Check your wiring and ensure that what you
specify in software matches your hardware
configuration; see the instructions in Chapter 3.

The module is out of calibration.

DT9837 Series modules are calibrated at thefactory. If you want to readjust the calibration of
the analog input or analog output circuitry using
Windows, refer to Chapter 8.

Your operating system does not have theappropriate Service Pack installed.

If using Windows, ensure that you load theappropriate Windows Service Pack. If you are
unsure of whether you are using USB 2.0 or
USB 1.1, run the Open Layers Control Panelapplet, described in Chapter 2.

Standby mode is enabled on your PC.

For some PCs, you may need to disable
standby mode on your system for proper USB
2.0 operation. Consult Microsoft for more
information.

107

Chapter 7

Technical Support
If you have difficulty using a DT9837 Series module, Data Translation’s Technical Support
Department is available to provide technical assistance.
To request technical support, go to our web site at http://www.mccdaq.com and click on the
Support link.
When requesting technical support, be prepared to provide the following information:• Your product serial number• The hardware/software product you need help on• The version of the OMNI CD or UL for Linux that you are using• Your contract number, if applicable
If you are located outside the USA, contact your local distributor; see our web site(www.mccdaq.com) for the name and telephone number of your nearest distributor.

108Troubleshooting

If Your Module Needs Factory Service
Most hardware models can be functionally tested, evaluated for repairs (if needed), andcalibrated to factory specifications. An RMA# must be obtained from Applications
Engineering in advance of sending any product back to Measurement Computing (DataTranslation is a Measurement Computing company). Customers outside the USA must
contact their local distributor for a return procedure. Calibration certificates for most analog
models can be obtained for a fee (certificate must be requested at time of RMA# assignment).

109

Chapter 7110

8Calibration (Windows Only)
Using the Calibration Utility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Calibrating the Analog Input Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Calibrating the Analog Output Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

111

Chapter 8

Overview
Note: The DT9837 Series Calibration Utility is provided for Windows only. Before using thecalibration utility, ensure that you installed the device driver for your module using the Data
Acquisition OMNI CD.

DT9837 Series modules are calibrated at the factory and should not require calibration for
initial use. We recommend that you check and, if necessary, readjust the calibration of theanalog input and analog output circuitry every six months using the DT9837 Series
Calibration Utility.
This chapter describes how to calibrate the analog input and output subsystems of a DT9837
Series module using the calibration utility.

112

Calibration (Windows Only)

Using the Calibration Utility
Start the DT9837 Series Calibration Utility as follows:
1. Click Start from the Task Bar.
2. For the DT9837 module, select Programs | Data Translation, Inc | Calibration | DT9837
Series Calibration Utility.
The main window of the DT9837 Series Calibration Utility appears.
3. Select the module to calibrate, and then click OK.
Once the calibration utility is running, you can calibrate the analog input circuitry (either
automatically or manually), described on page 114, or the analog output circuitry of themodule, described on page 116.

113

Chapter 8

Calibrating the Analog Input Subsystem
This section describes how to use the calibration utility to calibrate the analog input
subsystem of a DT9837 Series module.
DT9837 Series modules have separate calibration for each A/D input channel.

Connecting a Precision Voltage Source
To calibrate the analog input circuitry, you need to connect an external +9.3750 V precisionvoltage source to the DT9837 Series module. Connect the precision voltage source to the firstchannel you want to calibrate; for example, Analog In 0 (AD Ch0).

Using the Auto-Calibration Procedure
Auto-calibration is the easiest to use and is the recommended calibration method. To
auto-calibrate the analog input subsystem, do the following:
1. Select the A/D Calibration tab of the calibration utility.
2. Under the Calibration Settings area of the window, select the sampling frequency, in
Hertz, and the gain that you want to use.
Note: By default, this utility uses DC coupling with the current source disabled. This is
the recommended setting for most users. While changing these settings is not advised formost users, users with unique applications can change these settings by clicking theAdvanced button.
3. Under the Automatic Calibration area of the window, select the channel that you want tocalibrate from the Type of Calibration drop-down list box, and then click the Start button.
A message appears notifying you to verify that 0.000 V is applied to the channel.
4. Verify that the supplied voltage to your selected channel is 0.000 V, and then click OK.
The offset value is calibrated. When the offset calibration is complete, a message appears notifying
you to set the input voltage of the channel to +9.375 V.
5. Check that the supplied voltage to your selected channel is +9.375 V, and then click OK.
The gain value is calibrated and a completion message appears.
6. Repeat these steps for each analog input channel on the module.

Note: At any time, you can click Restore Factory Settings to reset the A/D calibration
values to their original factory settings. This process will undo any auto or manual calibration
settings.

114

Calibration (Windows Only)

Using the Manual Calibration Procedure
If you want to manually calibrate the analog input circuitry instead of auto-calibrating it, do
the following for each channel:
1. Select the A/D Calibration tab of the calibration utility.
2. Under the Calibration Settings area of the window, select the sampling frequency, in
Hertz, and the gain that you want to use.
Note: By default, this utility uses DC coupling with the current source disabled. This is
the recommended setting for most users. While changing these settings is not advised formost users, users with unique applications can change these settings by clicking theAdvanced button.
3. Under the Manual Calibration area of the window, select the channel that you want tocalibrate, and then click the Start button.
4. Adjust the offset as follows:a. Verify that 0.000 V is applied to the channel that you want to calibrate.
The current voltage reading for this channel is displayed in the AD Value box.
b. Adjust the offset by entering values between 0 and 255 in the Offset edit box, or byclicking the up/down buttons until the AD Value is 0.000 V.
5. Adjust the gain as follows:a. Verify that +9.375 V is applied to the channel that you want to calibrate.
The current voltage reading for this channel is displayed in the AD Value box.
b. Adjust the gain by entering values between 0 and 255 in the Gain edit box, or byclicking the up/down buttons until the AD Value is 9.3750 V.
6. Repeat these steps for each analog input channel on the module.

Note: At any time, you can click Restore Factory Settings to reset the A/D calibration
values to their original factory settings. This process will undo any auto or manual calibration
settings.

Once you have finished this procedure, continue with “Calibrating the Analog Output
Subsystem.”

115

Chapter 8

Calibrating the Analog Output Subsystem
This section describes how to use the calibration utility to calibrate the analog output
subsystem of a DT9837, DT9837A, or DT9837C module.
To calibrate the analog output circuitry, you need to connect an external precision voltmeter toanalog output channel 0 of the DT9837, DT9837A, or DT9837C module.
Do the following to calibrate the analog output circuitry:
1. Select the D/A Calibration tab of the calibration utility.
2. Connect an external precision voltmeter to Analog Output 0 (DAC Ch0) of the DT9837
Series module.
3. In the DAC Output Voltage box, select –9.375 V for the DT9837 and DT9837A, or –2.75 V
for the DT9837C.
4. Adjust the offset by entering values between 0 and 255 in the DAC 0 Offset edit box or byclicking the up/down buttons until the voltmeter reads –9.375 V for the DT9837 andDT9837A, or –2.75 V for the DT9837C.
5. In the DAC Output Voltage box, select 9.375 V for the DT9837 and DT9837A, or 2.75 V for
the DT9837C.
6. Adjust the gain by entering values between 0 and 255 in the DAC 0 Gain edit box or byclicking the up/down buttons until the voltmeter reads 9.375 V for the DT9837 andDT9837A, or 2.75 V for the DT9837C.

Note: At any time, you can click Restore Factory Settings to reset the D/A calibration
values to their original factory settings. This process will undo any D/A calibration settings.

Once you have finished this procedure, the analog output circuitry is calibrated. To close thecalibration utility, click the close box in the upper right corner of the window.

116

A
Specifications
Analog Input Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Analog Output Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Tachometer Input Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Gate Input Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Trigger Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
Master Oscillator Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Power, Physical, and Environmental Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Regulatory Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Connector Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

117

Appendix A

Analog Input Specifications
Table 22 lists the specifications for the analog input subsystem on the DT9837 Series modules.
Unless otherwise noted, specifications are typical at 25C.
Table 22: Analog Input Subsystem Specifications
FeatureDT9837
Specifications

DT9837A
Specifications

DT9837B
Specifications

DT9837C
Specifications

Number of analog input
channels4, single-ended,
simultaneous

4, single-ended,
simultaneous

4, single-ended,
simultaneous

4, single-ended,
simultaneous

Resolution

24 bits

24 bits

24 bits

24 bits

Ranges and gains
Gain of 1:
Gain of 10:

±10 V
±1 V

±10 V
±1 V

±10 V
±1 V

±10 V
±1 V

A/D type

Delta Sigma

Delta Sigma

Delta Sigma

Delta Sigma

Data encoding

Offset binary

Offset binary

Offset binary

Offset binary

Maximum sample rate

52.734 kHza52.734 kHza

105.469 kHZa

105.469 kHZa

Minimum sample rate

195.3 Hz195.3 Hz195.3 Hz195.3 Hz

Group delay

39/data rate, inseconds

39/data rate, inseconds

39/data rate, inseconds

39/data rate, inseconds

0.49 x sample
frequency, Hz

0.49 x sample
frequency, Hz

0.49 x sample
frequency, Hz

0.49 x sample
frequency, Hz

Passband ripple, ±0.005 dB:

0.453 x sample
frequency, Hz

0.453 x sample
frequency, Hz

0.453 x sample
frequency, Hz

0.453 x sample
frequency, Hz

Stopband, –100 dB:

0.547 x sample
frequency, Hz

0.547 x sample
frequency, Hz

0.547 x sample
frequency, Hz

0.547 x sample
frequency, Hz

400 kHz400 kHz400 kHz400 kHz

0.5 Hz0.1 Hz0.5 Hz

1 Hz> –110 dB with 50 
termination> –105 dB with 1 ktermination> –110 dB with 50 
termination> –105 dB with 1 ktermination> –110 dB with 50 
termination> –105 dB with 1 ktermination> –110 dB with 50 
termination> –105 dB with 1 ktermination

Input impedance

1 M 20 pFd

1 M 20 pFd

1 M 20 pFd

1 M 20 pFd

Coupling

AC/DC(software-selectable
per channel)

AC/DC(software-selectable
per channel)

AC/DC(software-selectable
per channel)

AC/DC(software-selectable
per channel)

IEPE current source

4 mA ±0.5%

4 mA ±0.5%

4 mA ±0.5%

2 mA ±0.5%

IEPE compliance voltage

18 V

18 V

18 V

18 V

ADC Delta Sigma filterb
Passband, –3 dB:

Analog filterb
Low pass cutoff, –3 dB:
High pass cutoff, –3 dB(AC coupling):
Channel-to-channel
crosstalkc
Input Signal = 10 kHz:118

Specifications
Table 22: Analog Input Subsystem Specifications (cont.)
DT9837
Specifications

FeatureIEPE current source noise
DC to 1 kHz

DT9837A
Specifications

DT9837B
Specifications

DT9837C
Specifications

5 nARMS

5 nARMS

5 nARMS

5 nARMS

Offset errore

1.5 mV

1.5 mV

1.5 mV

1.5 mV

Offset error temperature
coefficient(10 V/C x Gain) +100 V(10 V/C x Gain) +100 V(10 V/C x Gain) +100 V(10 V/C x Gain) +100 V

Gain error
Gain of 1:
Gain of 10:±0.02%±0.5%±0.02%±0.5%±0.02%±0.5%±0.02%±0.5%

Gain error temperature
coefficient

25 ppm//C

25 ppm//C

25 ppm//C

25 ppm//C

ADC Integral Non-Linearity
error, INL±0.0006% of full-scale
range±0.0006% of full-scale
range±0.0006% of full-scale
range±0.0006% of
full-scale range

ADC Differential
Non-Linearity error, DNL

Monotonic to 24 bits

Monotonic to 24 bits

Monotonic to 24 bits

Monotonic to 24 bits

–
–
–
–

16 bits±15 mV+0, –2%42 ns to 83 ns

–
–
–
–

–
–
–
–

DC Accuracy

D/A Readback in A/D Stream
A/D resolution:
Zero error:
Full-scale error:
Clock on input A/D Done
Dynamic Performancef
Maximum input voltage(without damage)Power on:Power off:

See Table 23 on page 120.

±30 V
±20 V

±40 V
±40 V

±40 V
±40 V

±40 V
±40 V

±40 V

±40 V

±40 V

±40 V

8 kV
4 kV

8 kV
4 kV

8 kV
4 kV

8 kV
4 kV

Overvoltage Protection
Overvoltage protection(power on/off)
ESD protection
Arc:
Contact:

a. For frequencies of 52.734 kHz or less, Conversion Rate = Sample Rate * 512.
For frequencies greater than 52.734 kHz, Conversion Rate = Sample rate * 256.
b. The total frequency response is the combined frequency response of the ADC Sigma Delta filter and the analog filter.
c. Channel 0 is the reference channel with a 20 V PP signal and a maximum sample rate of 52.734 kSamples/s.
d. Cable capacitance of typically 30 pF per foot must be added.
e. Offset errors are referred to the input.
f. ENOB, SINAD, SNR, THD, and SFDR measurements were made with a 16384 point FFT with a minimum 4-term Blackman Harris window.

119Appendix A
Table 23: Dynamic Performance Specifications
DT9837
Specifications

Dynamic Performancea

DT9837A
Specifications

DT9837B and DT9837C
Specifications

Gain of 1

Gain of 10

Gain of 1

Gain of 10

Gain of 1

Gain of 10

Effective Number of Bits, ENOBb(1 kHz input, 52.734 kSPS)–1 dBFS input:–6 dBFS input:

15.2 bits
15.8 bits

14.6 bits
15.3 bits

15.3 bits
16.3 bits

14.7 bits
15.6 bits

14.8 bits
16.0 bits

14.3 bits
15.4 bits

Signal to Noise and Distortion Ratio,
SINADc(1 kHz input)–1 dBFS input:–6 dBFS input:

92 dB
91 dB

88 dB
88 dB

93 dB
94 dB

89 dB
90 dB

90 dB
92 dB

87 dB
88 dB

Signal to Noise Ratio, SNRd
(1 kHz input)–1 dBFS input:–6 dBFS input:

95 dB
91 dB

94 dB
91 dB

98 dB
95 dB

96 dB
94 dB

97 dB
93 dB

95 dB
92 dB

Total Harmonic Distortion, THDe
(1 kHz input)–1 dBFS input:–6 dBFS input:–96 dB–104 dB–90 dB–91 dB–95 dB–102 dB–90 dB–92 dB–91 dB–99 dB–88 dB–91 dB

Spurious Free Dynamic Range, SFDRf(1 kHz input)–1 dBFS input:–6 dBFS input:

100 dBFS
110 dBFS

93 dBFS
101 dBFS

98 dBFS
108 dBFS

93 dBFS
100 dBFS

94 dBFS
107 dBFS

91 dBFS
100 dBFS

Noise Floor(50 input termination)

100 VRMS

10 VRMS

60 VRMS

10 VRMS

80 VRMS

9 VRMSa. ENOB, SINAD, SNR, THD, and SFDR measurements were made with a 16384 point FFT using a minimum 4-term Blackman Harris window at the
maximum sampling rate.
b. Effective Number of Bits (ENOB) is calculated from the SINAD value with adjustment for level below full-scale of the input signal.

 SINAD – 1.76 + IBFS ENOB = ---------------------------------------------------------6.02
where, IBFS is a positive value in dB, representing the ratio of a full-scale signal to the input signal.
c. Signal to Noise and Distortion (SINAD) is the ratio of the RMS value of the input signal to the RMS sum of all other spectral components,
excluding DC.
d. Signal to Noise Ratio (SNR) is the ratio of the RMS value of the input signal to the RMS sum of all other spectral components, excluding harmonics
and DC.
e. Total Harmonic Distortion (THD) is the ratio of the RMS value of the input signal to the RMS sum of all harmonics.
f. Spurious Free Dynamic Range (SFDR) is the ratio of the RMS full-scale range to the RMS value of the largest peak spurious component, including
harmonics.

120

Specifications

Analog Output Specifications
Table 24 lists the specifications for the analog output subsystem on the DT9837, DT9837A, andDT9837C modules. Unless otherwise noted, specifications are typical at 25C.
Table 24: Analog Output Subsystem Specifications
FeatureDT9837 Specifications

DT9837A Specifications

DT9837C Specifications

Number of analog output
channels111Resolution

24 bits

24 bits

24 bits

D/A type

Delta Sigma

Delta Sigma

Delta Sigma

Output range

±10 V

±10 V

±3 V

Data encoding

Offset binary

Offset binary

Offset binary

Minimum sample frequency

46.875 kHz

10 kHz

10 kHzMaximum sample frequency

46.875 kHz

52.734 kHz

96.0 kHzGroup delay (typical)

34/sample rate, in s

29/sample rate, in s

29/sample rate, in s

D/A master clock range

output frequency x 256

output frequency x 512

output frequency x 512

DAC Delta Sigma filtera
Passband, –3 dB:
Passband ripple, ±0.002 dB:
Stopband, –82 dB:

0.49 x sample frequency, Hz
0.454 x sample frequency, Hz
0.546 x sample frequency, Hz

0.49 x sample frequency, Hz
0.454 x sample frequency, Hz
0.5646 x sample frequency, Hz

0.49 x sample frequency, Hz
0.454 x sample frequency, Hz
0.5646 x sample frequency, Hz

Analog filtera

10 kHz, 2-pole, low-pass
Butterworth

10 kHz, 2-pole, low-pass
Butterworth

40 kHz smoothing filter

Output current±1 mA maximum load (10 V
across 10 K)±3 mA maximum load (10 V across 3.3 K)±2 mA maximum load (3 V across 1.5 K)

Output FIFO

8192 Samples, total

8192 Samples, total

8192 Samples, total

Idle channel noise(216 kSPS)

600 VRMS

100 VRMS

30 VRMS–80 dB–78 dB–97 dB–80 dB–78 dB–100 dB

84 dBFS

88 dBFS

100 dBFS

86 dBFS

88 dBFS

109 dBFS

Offset error±1.5 mV±1.5 mV±1.5 mV

Offset error temperature
coefficient

200 V/C

200 V/C

200 V/C

Gain error±3.0%±0.03%±0.03%

Total Harmonic Distortion, THDb
–1 dBFS, 1 kHz output,
10 k load:–6 dBFS, 1 kHz output,
10 k load:
Spurious Free Dynamic Range,
SFDRb–1 dBFS, 1 kHz output,
10 k load:–6 dBFS, 1 kHz output,
10 k load:

121

Appendix A
Table 24: Analog Output Subsystem Specifications (cont.)
FeatureGain error temperature
coefficient

DT9837 Specifications
50 ppm/C

Power fault and reset
ESD protection
Arc:
Contact:

DT9837A Specifications
50 ppm/C

DT9837C Specifications
50 ppm/C

Goes to 0 V ±10 mV if the USB cable is removed or the power fails
8 kV
4 kV

8 kV
4 kV

8 kV
4 kV

a. The total frequency response is the combined frequency response of the DAC Sigma Delta filter and the analog filter.
b. THD and SFDR measurements were made with a 16384 point FFT using a minimum 4-term Blackman Harris window at the maximum sample
rate.

122

Specifications

Tachometer Input Specifications
Table 25 lists the specifications for the tachometer input on the DT9837, DT9837A, andDT9837B modules. The tachometer is not supported by the DT9837C module.
Table 25: Tachometer Input Specifications
DT9837
Specifications

FeatureDT9837A
Specifications

DT9837B
Specifications

Number of channels

1

1

1

Resolution

31 bits per channel

31 bits per channel

31 bits per channel

Input voltage range

±30 V

±30 V

±30 V

Threshold voltage+2 V with 0.5 V
hysteresis+2 V with 0.5 V
hysteresis+2 V with 0.5 V
hysteresis

Maximum input frequency

380 kHz

1 MHz

1 MHz

Minimum pulse width high/low(minimum amount of time it takes a
C/T to recognize an input pulse)

1.3 s0.4 s0.4 sClock frequency for tachometercounter 0 measurements

12 MHz(83 ns resolution)

12 MHz(83 ns resolution)

12 MHz(83 ns resolution)

Clock frequency for tachometercounter 1 measurements–

48 MHz(21 ns resolution)

48 MHz(21 ns resolution)

123

Appendix A

Gate Input Specifications
Table 26 lists the specifications for the gate input on the DT9837A-OEM and DT9837B
modules.
Table 26: Gate Input Specifications
DT9837A-OEM and DT9837B
Specifications

Feature124

Signal type

LVTTL

Input voltage range for gate input signal

0 to 5 V

Threshold voltage±2 V with 0.5 V hysteresis

Maximum input frequency

1 MHz

Minimum pulse width (high/low)

0.4 sCounter resolution

32 bits

Clock frequency for gate counter 2
measurements

48 MHz (21 ns resolution)

Specifications

Trigger Specifications
Table 27 lists the specifications for the trigger on the DT9837 Series modules.
Table 27: Trigger Specifications
FeatureDT9837 Specifications

DT9837A and DT9837B
Specifications

Trigger sources
Internal software trigger:
External digital trigger:
Analog threshold trigger:

Software-initiatedSoftware-selectable
Software-selectable

External digital trigger
Input type:
Logic family:
Input logic load:
Lower threshold:
Upper threshold:
Hysteresis:
Input sink current:
Minimum pulse width high/low:
Maximum input signal:
Analog threshold trigger
Type:

DT9837C Specifications

Edge-sensitive, positive trigger
LVTTL inputs
1 LVTTL
1.1 V
1.3 V
0.2 V
33 A
1.3 A±30 V

Threshold level:

Positive threshold trigger on
analog input channel 0
1.0 V

Positive threshold trigger on
analog input channel 0+0.2 to +9.8 V

Hysteresis:

100 mV

100 mV

Positive or negative threshold
trigger on any analog input channel±10 V for a gain of 1;±1 V for a gain of 10
100 mV

1 conversion period maximum

1 conversion period maximum

1 conversion period maximum

Trigger delay

125Appendix A

Master Oscillator Specifications
Table 28 lists the specifications for the master oscillator on the DT9837A, DT9837B, andDT9837C modules.
Table 28: Master Oscillator Specifications
Feature126

DT9837A, DT9837B, andDT9837C Specifications

Frequency

48 MHzAccuracy at 25 C±30 ppm

Drift over temperature 0 to 70C(Total)±50 ppm

Aging (first year)±5 ppmMaximum error (first year)±85 ppm

Specifications

Power, Physical, and Environmental Specifications
Table 29 lists the power, physical, and environmental specifications for the DT9837 Series
modules.
Table 29: Power, Physical, and Environmental Specifications
FeaturePower, +5 V
PhysicalDimensions of enclosure:

Dimensions of PCB only:

Weight:
PCB assembly with enclosure:
PCB assembly:
Environmental
Operating temperature range:
Storage temperature range:
Relative humidity:
Altitude:DT9837
Specifications±0.5 V@ 0.5 A

DT9837A
Specifications±0.30 V@ 0.5 A

DT9837B
Specifications±0.30 V @ 425 mA

DT9837C
Specifications±0.30 V@ 0.5 A

Width = 105.9 mm
Length = 189 mm
Height = 40 mm
Width: 100 mm
Length: 146.6 mm
Thickness: 1.6 mm
490.7 g153.1 g0C to55C–25C to 85C

to 95%, noncondensing
up to 10,000 feet127Appendix A

Regulatory Specifications
The DT9837 Series is CE-compliant. Table 30 lists the regulatory specifications for the DT9837
Series modules.
Table 30: Regulatory Specifications
FeatureDT9837 Series Specifications

Emissions (EMI)FCC Part 15, Class A
EN55011:2007 (Based on CISPR-11, 2003/A2, 2006)

Immunity

EN61326-1:2006
Electrical Equipment for Measurement, Control, and Laboratory
Use
EMC Requirements
EN61000-4-2:2009
Electrostatic Discharge (ESD) 4 kV contact discharge,
8 kV air discharge, 4 kV horizontal and vertical coupling planes
EN61000-4-3:2006
Radiated electromagnetic fields, 3 V/m, 80 to 1000 MHz;
3 V/m, 1.4 GHz to 2 GHz; 1 V/m, 2 GHz to 2.7 GHz
EN61000-4-4:2004
Electrical Fast Transient/Burst (EFT) 1 kV on data cables
EN61000-4-6:2009
Conducted immunity requirements, 3 Vrms on data cables
150 kHz to 80 MHz

RoHS (EU Directive 2002/95/EG)

128

Compliant (as of July 1st, 2006)

Specifications

Connector Specifications
Table 31 lists the connector specifications for the DT9837A, DT9837A-OEM, DT9837B, andDT9837C modules.
Table 31: Connector Specifications
FeatureSpecifications

RJ45 (LVDS) Connector

Molex part number 44661-0001

Gate Input Connectora

AMP/Tyco part number 5-146282-4

BNC Connectors(DT9837, DT9837A, DT9837B, and DT9837C-BNC)

Amphenol 31-5540

Mini-XLR connectors (DT9837C-XLR)

Switchcraft TRAPC3MX

a. This connector is available on the DT9837A-OEM module only.

129

Appendix A

130

B
Connector Pin Assignments and
LED Status Indicators
RJ45 (LVDS) Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Gate Input Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
LED Status Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

131

Appendix B

RJ45 (LVDS) Connector
Figure 27 shows the RJ45 (LVDS) synchronization connector.

Figure 27: RJ45 (LVDS) Synchronization Connector

Table 32 lists the pin assignments for the RJ45 (LVDS) synchronization connector on theDT9837A, DT9837A-OEM, DT9837B, and DT9837C modules.
Table 32: RJ45 (LVDS) Synchronization Connector Pin Assignments
Pin

132

Description

1

Clock +
(An LVDS signal for synchronizing data collection between two modules.)2

Clock –

3

Trigger +(An LVTTL signal that is asserted low for triggering between modules.)4

Sync +(An LVTTL signal that is asserted low for synchronizing all the analog
input signals between modules for simultaneous sample-and-holdapplications.)

5

Sync –(Connected to digital ground through a 100  resistor.)

6

Trigger –(Connected to digital ground through a 100  resistor.)

7

No Connect

8

No Connect

Connector Pin Assignments and LED Status Indicators

Gate Input Connector
The 4-pin Gate Input connector is available on the DT9837A-OEM module only. (The DT9837B
module uses a BNC for the gate input signal). Figure 28 shows the orientation of the Gate
Input connector on the DT9837A-OEM module.

Pin 3

Pin 4

Pin 1

Pin 2

Figure 28: Gate Input Connector

Table 33 lists the pin assignments for the Gate Input connector on the DT9837A-OEM module.
Table 33: Gate Input Connector Pin Assignments
Pin

Description

1

Gate Input

2

No Connect

3

Digital Ground4

No Connect133Appendix B

LED Status Indicators
The DT9837 Series has a single bi-color LED that indicates the status of the module, as
described in Table 34.
Table 34: LED Status Indicators on the DT9828 Module
Color of the LED

134

Status Description

Green

Module is powered

Blinking Amber

Module is acquiring data

C
Register-Level Programming
DT9837 Register-Level Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
DT9837A, DT9837B, and DT9837C Register-Level Programming . . . . . . . . . . . . . . . . . . . 140

135

Appendix C

DT9837 Register-Level Programming
If you need to change the settings of the Open Layers Control Panel for the DT9837
programmatically, you can write to the following registers of the DT9837 module:• General Control Register 2 – Write to this memory location to change the tachometersettings.
• EEPROM – Write to this memory location to change the coupling type, current source, orhigh power mode settings.
If you are using Windows, you can use the Data Acq SDK function olDiagWriteReg to write
to these registers.
The following subsections describe writing to these memory locations in more detail.

Writing to the General Control Register 2
Table 35 describes the bits of General Control Register 2 on the DT9837 module that relate to
the programmable settings in the Open Layers Control Panel, described on page 36.
Table 35: DT9837 General Control Register 2
Bits

Type

Name

Description

[7]

RW

Tach Counter 0 Start SelectSelect the starting edge for the period measurement on
Tach Counter 0:
0 – Tach Input Rising Edge
1 – Tach Input Falling Edge

[5]

RW

Tach Counter 0 Mode SelectSelect the value read in between measured values on
Tach Counter 0:
0 – Previous measurement
1 – Zeros[4]

RW

Tach Counter 0 Flag SelectSelect whether or not to use the Stale Data flag:
0 – Stale Data flag not used
1 – Stale Data flag used

The following Windows example shows how to update the bits of General Control Register 2
on the DT9837 module using the value specified in the RegValueToWrite variable:#define LOCAL_BUS_BASE 0x200000#define GENERAL_CNTRL_REG2 (LOCAL_BUS_BASE | 0x4102)
olDiagWriteReg (m_hDev, GENERAL_CONTROL_REG2, RegValueToWrite,2);
General Control Register 2 (ControlReg2) Offset: 0x2

Note: The contents of the registers are reset once the application exits.

136

Register-Level Programming

Writing to EEPROM to Change the Coupling Type and Current
SourceThe Open Layers Control Panel has controls for setting the coupling type and current source
for analog input channels 0, 1, 2, and 3, and for keeping the high power mode always on or off.
You can change these settings programmatically by writing to the EEPROM on the DT9837
module.
The EEPROM_OFFSET_SETTINGS control (15) is used to store the coupling type and current
source values for the DT9837. Table 36 describes the bit values in the
EEPROM_OFFSET_SETTINGS control that are used to store the coupling type and current
source values on the DT9837 module.
Table 36: DT9837 EEPROM Byte (EEPROM_OFFSET_SETTINGS)
for the Coupling Type and Current Source
Bits

Type

Default

Name

Description

[0]

RW

1

ADC 0 Coupling

Select the coupling type for analog input
channel 0:
0 – AC
1 – DC[1]

RW

1

ADC 1 Coupling

Select the coupling type for analog input
channel 1:
0 – AC
1 – DC[2]

RW

1

ADC 2 Coupling

Select the coupling type for analog input
channel 2:
0 – AC
1 – DC[3]

RW

1

ADC 3 Coupling

Select the coupling type for analog input
channel 3:
0 – AC
1 – DC[4]RW

1

ADC 0 Current Source

Select whether or not to use the 4 mA current
source for analog input channel 0:
0 – Enabled
1 – Disabled

[5]

RW

1

ADC 1 Current Source

Select whether or not to use the 4 mA current
source for analog input channel 1:
0 – Enabled
1 – Disabled

[6]

RW

1

ADC 2 Current Source

Select whether or not to use the 4 mA current
source for analog input channel 2:
0 – Enabled
1 – Disabled

[7]

RW

1

ADC 3 Current Source

Select whether or not to use the 4 mA current
source for analog input channel 3:
0 – Enabled
1 – Disabled137

Appendix C
In Windows, you can read this EEPROM location programmatically using theolDiagReadReg() function, and write to the EEPROM location programmatically using theolDiagWriteReg() function. To change a single bit requires a read/modify/write operation.
The following constants define the location of the registers in EEPROM:#define EEPROM_MEM_BASE 0x100000
const ULONG EEPROM_OFFSET_SETTINGS = 15;This Windows example shows how to read the current source and coupling type from the
EEPROM:ULONG olddata;
OLSTATUS olStatus = olDiagReadReg(m_hDev, EEPROM_MEM_BASE +EEPROM_OFFSET_SETTINGS, &olddata, 1);
This Windows example shows how to write values to EEPROM to change the current source
and coupling type:ULONG newdata;
OLSTATUS olStatus = olDiagWriteReg(m_hDev, EEPROM_MEM_BASE +EEPROM_OFFSET_SETTINGS, newdata, 1);

Note: The data must be read and written as a 32-bit value, but only the lower 8-bits of thisvalue is actually transferred.

Writing to EEPROM to Change the High Power Mode
For the high power mode setting, you can keep high power mode always turned on or turn offhigh power mode (the default setting) by writing to the
EEPROM_OFFSET_POWER_OVERRIDE_REG (0x000E) control in the EEPROM.
Turning off the high-power circuitry (writing a value of 0 to this control) helps to conserve
power, which may be useful when the module is used with a laptop. However, to ensure thatthe module is warmed up and that any settling time errors of the IEPE current source areminimized, it is recommended that you keep the module’s high-power circuitry always
turned on by writing a value of 1 to this control.
In Windows, you can read the EEPROM location programmatically using theolDiagReadReg() function, and write to the EEPROM location programmatically sing theolDiagWriteReg() function. To change a single bit requires a read/modify/write operation.
The following constants define the location of the registers in EEPROM:#define EEPROM_MEM_BASE 0x100000#define EEPROM OFFSET_POWER_OVERRIDE_REG 0x000E

138

Register-Level Programming
This Windows example shows how to read the high power mode value from the EEPROM:ULONG alwaysOn = 1;
UINT numberOfBytes = 1;
OLSTATUS olStatus = olDiagReadReg(m_hDev, EEPROM_MEM_BASE +EEPROM_OFFSET_POWER_OVERRIDE_REG, &alwaysOn, numberOfBytes);
This Windows example shows how to write to this EEPROM location to keep high powermode always on:// To keep the high power mode always on, use the following code:
UINT alwaysOn = 1;
UINT numberOfBytes = 1;
OLSTATUS olStatus = olDiagWriteReg(m_hDev, EEPROM_MEM_BASE +EEPROM_OFFSET_POWER_OVERRIDE_REG, alwaysOn, numberOfBytes);

Note: Currently, only one bit of this control is used; therefore, there is no need to mask anyother bits in this control.

139

Appendix C

DT9837A, DT9837B, and DT9837C Register-Level
Programming
If you need to change the settings of the Open Layers Control Panel for the DT9837A,
DT9837B, or DT9837C programmatically, you can write to the following registers of theDT9837A, DT9837B, or DT9837C module:• General Control Register 4 – Write to this memory location to change the tachometer andgate settings. The DT9837C module does not support this register.
• EEPROM – Write to this memory location to change the coupling, current source, andhigh power mode settings.
In Windows, you can write to these registers using the Data Acq SDK function
olDiagWriteReg.
If you are using Linux or macOS, refer to page 147 for more information on writing to theseregisters.
The following subsections describe writing to these memory locations in more detail.

Writing to the General Control Register 4
Table 37 describes the bits of General Control Register 4 on the DT9837A and DT9837B,
modules that relate to the tachometer and gate settings in the Open Layers Control Panel,described on page 36.
Table 37: DT9837A and DT9837B General Control Register 4

140

Bits

Type

Name

Description[15:14]RW

Tach Counter 1 Start SelectSelect the starting edge for the Tach Counter 1
measurement function:
00 – A/D Ready Falling Edge
01 – Reserved
10 – Tach Input Falling Edge
11 – Tach Input Rising Edge

[13:12]RW

Gate Counter 2 Start SelectSelect the starting edge for the Gate Counter 2
measurement function:
00 – A/D Ready Falling Edge
01 – Reserved
10 – Gate Falling Edge
11 – Gate Rising Edge

[11:10]RW

Gate Counter 2 Stop SelectSelect the stopping edge for the Gate Counter 2
measurement function:
00 – A/D Ready Falling Edge
01 – Reserved
10 – Gate Falling Edge
11 – Gate Rising Edge

Register-Level Programming
Table 37: DT9837A and DT9837B General Control Register 4 (cont.)
Bits

Type

Name

Description

[8]

RW

Gate Counter 2 Self Clear

Select the value read in between measured values on
Gate Counter 2:
0 – Keep the last value
1 – Clear to 0 on write to Input FIFO

[7:6]

RW

Tach Counter 1 Stop SelectSelect the stopping edge for the Tach Counter 1
measurement function:
00 – A/D Ready Falling Edge
01 – Reserved
10 – Tach Input Falling Edge
11 – Tach Input Rising Edge

[4]

RW

Tach Counter 1 Self Clear

Select the value read in between measured values on
Tach Counter 1:
0 – Keep the last value
1 – Clear to 0 on write to Input FIFO

[3]

RW

Tach Counter 0 Start SelectSelect the starting edge for the period measurement on
Tach Counter 0:
0 – Tach Input Rising Edge
1 – Tach Input Falling Edge

[1]

RW

Tach Counter 0 Mode SelectSelect the value read in between measured values on
Tach Counter 0:
0 – Previous measurement
1 – Zeros[0]

RW

Tach Counter 0 Flag SelectSelect whether or not to use the Stale Data flag:
0 – Stale Data flag not used
1 – Stale Data flag used

The following Windows example shows how to update the bits of General Control Register 4
on the DT9837A and DT9837B modules using the value specified in the RegValueToWrite
variable:#define LOCAL_BUS_BASE 0x400000#define GENERAL_CNTRL_REG4 (LOCAL_BUS_BASE | 0x8)
olDiagWriteReg (m_hDev, GENERAL_CONTROL_REG4,RegValueToWrite,2);
General Control Register 4 (ControlReg4) Offset: 0x8

Note: The contents of the registers are reset once the application exits.

141

Appendix C

Writing to EEPROM
On the DT9837A, DT9837B, and DT9837C modules, the Open Layers Control Panel has
controls for setting the following parameters, which are stored in 8 consecutive bytes of
EEPROM:• Channel 0, 1, 2 and 3 Coupling type. The values AC or DC are stored as constants for thesecontrols.
• Channel 0, 1, 2 and 3 Current Source. The values INTERNAL, EXTERNAL or DISABLED
are stored as constants for these controls. Note that while the control panel has only two
states (Enabled and Disabled), three states are actually defined, as follows: INTERNAL = Enabled (used by the control panel) EXTERNAL = Disabled DISABLED = Disabled (used by the control panel)• High power mode. You can keep high power mode always turned on or turn off highpower mode (the default setting). Turning off the high-power circuitry helps to conserve
power, which may be useful when the module is used with a laptop. However, to ensurethat the module is warmed up and that any settling time errors of the IEPE current source
are minimized, it is recommended that you keep the module’s high-power circuitry
always turned on.
To keep high power mode always on, set the value of this control to True. To turn off highpower mode, set the value of this control to False.
These controls may also be “uninitialized” if for some reason, the module skipped thepost-manufacturing initialization process.
If you are using Linux or macOS, these settings are programmed using software commands;
refer to page 147 for more information.
In Windows, you can access the storage locations programmatically using theolDiagReadReg() and olDiagWriteReg() functions. The following code shows the location ofthese controls in the register map:
#define EEPROM_MEM_BASE
0x100000// Coupling storage offsets relative to the base address for the// four analog input channels
const EEPROM_OFFSET_COUPLING_0 = 0x0020;
const EEPROM_OFFSET_COUPLING_1 = 0x0021;
const EEPROM_OFFSET_COUPLING_2 = 0x0022;
const EEPROM_OFFSET_COUPLING_3 = 0x0023;// Current source storage offsets relative to the base address for// the four analog input channels
const EEPROM_OFFSET_CURRENT_SOURCE_0 = 0x0024;
const EEPROM_OFFSET_CURRENT_SOURCE_1 = 0x0025;
const EEPROM_OFFSET_CURRENT_SOURCE_2 = 0x0026;
const EEPROM_OFFSET_CURRENT_SOURCE_3 = 0x0027;// High power mode offset relative to the base address
const EEPROM_OFFSET_POWER_OVERRIDE_REG = 0x0040;

142

Register-Level Programming

Note: olDiagReadReg() and olDiagWriteReg() require a ULONG value for the data
parameter, but we are reading and writing only a single byte (last parameter).

// To read the current source power-up default for channel 2,// use the following code:
ULONG Channel_2_Current_Source;
OLSTATUS olStatus = olDiagReadReg(m_hDev, EEPROM_MEM_BASE +EEPROM_OFFSET_CURRENT_SOURCE_2, &Channel_2_Current_Source, 1);// To set the coupling power-up default for channel 0 to AC,// use the following code:
OLSTATUS olStatus = olDiagWriteReg(m_hDev, EEPROM_MEM_BASE +EEPROM_OFFSET_COUPLING_0, (ULONG) AC, 1);// To keep the high power mode always on, use the following code:
BOOL alwaysOn = True;
UNIT numberOfBytes = 1;
OLSTATUS olStatus = olDiagWriteReg(m_hDev, EEPROM_MEM_BASE +EEPROM_OFFSET_POWER_OVERRIDE_REG, alwaysOn, numberOfBytes);143

Appendix C

144

D
Programming in Linux or macOS
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Installing UL for Linux . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Using UL for Linux . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

145

Appendix D

Overview
If you want to program a Data Translation DT9837A, DT9837B, or DT9837C module in Linuxor macOS rather than in Windows, use the Universal Library (UL) for Linux from
Measurement Computing Corporation instead of DT-Open Layers.

Note: UL for Linux does not support the DT9837 module. Also note that user calibration is
supported only in Windows using the DT9837 Series Calibration Utility.

Installing UL for Linux
Follow the instructions from github at https://github.com/mccdaq/uldaq to build and install
UL for Linux.

Using UL for Linux
Refer to the examples and online help provided with UL for Linux for information on how todevelop applications for data acquisition devices using C or Python on the Linux or macOS
operating system.
Listed below are particular notes to be aware of when using UL for Linux with the DT9837A,
DT9837B, or DT9837C modules.

Channel Numbering in UL for Linux
When using UL for Linux with Data Translation devices, you must specify the channels
differently for scans than in DT-Open Layers.
In DT-Open Layers scanned data is accessed through the analog input subsystem, and eachchannel number in the channel list specifies the analog or counter channel to be scanned. In
UL for Linux, scanned data is accessed through the corresponding subsystem type, andchannel numbers for each subsystem type start at 0.
For example, to get scan data on the DT9837B using UL for Linux, keep the following in mind:• To get analog input data only, use ulAInScan and specify the analog input channels tosample (0 to 3).
• To get data from tachometer channel 0 only, use ulCInScan and specify channel 0.
• To get data from tachometer channel 1 only, use ulCInScan and specify channel 1.
• To get data from gate counter 2 only, use ulCInScan and specify channel 2.
• To get data from all these channels at once, use ulDaqInScan, and specify the channel
number (starting at 0) and the channel type (such as analog or counter) in the
DaqInChanDescriptor structure.

146

Programming in Linux or macOSIEPE Settings for Analog Inputs
In Windows, you can use the Open Layers Control panel to configure the IEPE settings thatare used at power up.
In UL for Linux, IEPE is always off at power up. The current source is disabled and DC
coupling is used for the analog input channels by default.
To configure the current source in UL for Linux, use the function ulAISetConfig with theconfigItem AI_CFG_CHAN_IEPE_MODE. Specify IEPE_DISABLED or IEPE_ENABLED forthe configValue.
To configure the coupling mode (DC or AC) in UL for Linux, use the function ulAISetConfig
with the configItem AI_CFG_CHAN_COUPLING_MODE. Specify CM_DC or CM_AC for theconfigValue.
To set the sensor sensitivity of your IEPE input in UL for Linux, use the function
ulAISetConfigDbl with the configItem AI_CFG_CHAN_SENSOR_SENSITIVITY. For
configValue, specify a floating point number for the sensitivity.

Note: The values that are set using ulAISetConfig and ulAISetConfigDbl are not retainedin EEPROM; therefore, they are not used a power up. It is recommended that your program
initialize these values when your program runs.

Tachometer Measurements
In Windows, you can use the Open Layers Control panel to configure the settings that areused at power up for the tachometer (tachometer counter 0 and tachometer counter 1).
In UL for Linux, the DT9837A and DT9837B always power up with the values for thetachometer that were set through the Open Layers Control Panel. (The DT9837C does notsupport tachometer inputs.)

Frequency and Period Measurement - Tachometer Counter 0
In UL for Linux, you can read the number of counts between two consecutive starting edges of
the tachometer input signal by using ulCInScan function and specifying channel 0 or by using
the ulDaqInScan function and specifying channel number 0 and the counter channel type in
the DaqInChanDescriptor structure.
You can configure the settings for the measurement using the ulCtrSetConfig function withthe configItem CTR_CFG_REG. This configItem is used to write to General Control Register 4,
described in Table 38 on page 148.

147

Appendix D
Table 38: General Control Register 4
MSB

14

T1 ST

13

12

G2 ST

Gate Counter 2 Self Clear0
G2 CLR

1

G2 STP

8

G2 STP

X

G2
CLR

Select value read between measured
values on Gate Counter 2

Select stopping edge forGate Counter 2 measurement function

7

6

T1 STP

T0 FLG

10Gate Input Falling Edge

11

Gate Input Rising Edge

Select starting edge forGate Counter 2 measurement function

00

A/D Ready Falling Edge

01

Reserved

10Gate Input Falling Edge

3

2

1

LSB

X

T1
CLR

T0
ST

X

T0
MD

T0
FLG

Stale Data flag not used1

Stale Data flag used

Select starting edge for
Tach Counter 1 measurement function

00

A/D Ready Falling Edge

01

Reserved

1011

T1 CLR

Select value read between measured
values on Tach Counter 00Previous measurement

1

Zeros

Tach Counter 0 Start SelectT0 ST

Select whether or not to use the Stale
Data flag

0

Select starting edge for
Tach Counter 0 measurement function

0

Tach Input Falling Edge

1

Tach Input Rising Edge

Tach Counter 1 Self Clear

Gate Input Rising Edge

Tach Counter 1 Start Select4

Tach Counter 0 Mode SelectT0 MD

Reserved

5

Tach Counter 0 Flag SelectA/D Ready Falling Edge

01

11

T1 ST

9

Clear to 0 on write to Input FIFO

Gate Counter 2 Start Select

G2 ST

10

Keep the last value

Gate Counter 2 Stop Select00

11Select value read between measured
values on Tach Counter 1

0

Keep the last value

1

Clear to 0 on write to Input FIFO

Tach Counter 1 Stop SelectSelect stopping edge for
Tach Counter 1 measurement function

00

A/D Ready Falling Edge

01

Reserved

Tach Input Rising Edge

10

Tach Input Rising Edge

Tach Input Falling Edge

11

Tach Input Falling Edge

T1 STP

Specify the appropriate bitmask value for the register using the configValue argument of theulCtrSetConfig function. (You can first read the value of the register using theulCtrGetConfig function with the configItem CTR_CFG_REG to make this easier.)148

Programming in Linux or macOS

Note: The values that are set using ulCtrSetConfig are not retained in EEPROM; therefore,
they are not used at power up. It is recommended that your program initialize these values
when your program runs.

The following settings are configurable for tachometer counter 0 using configItem
CTR_CFG_REG and the ulCtrSetConfig function:• Tach Counter 0 Start Select (T0 ST, bit 3 of General Control Register 4) – Set bit 3 to a valueof 1 (Tach Input Falling Edge) to start the measurement on the falling edge of thetachometer input signal, or to a value of 0 (Tach Input Rising Edge) to start themeasurement on the rising edge of the tachometer input signal.
• Tach Counter 0 Mode Select (T0 MD, bit 1 of General Control Register 4) – Set bit 1 to avalue of 1 (Zeros) to read a value of 0 between measurements, or to a value of 0 (Previous
measurement) if you want to read the previous measurement value if the newmeasurement value is not yet complete.
• Tach Counter 0 Flag Select (T0 FLG, bit 0 of General Control Register 4) – Set bit 0 to avalue of 1 (Stale Data flag used) if you want to indicate whether or not the measurement
value is new, or to a value of 0 (Stale Data flag not used) if you do not want to indicate
whether the measurement value is new.
If the Stale Data flag is used, the most significant bit (MSB) of the measurement value isset to 0 to indicate new data; reading the value before the measurement is complete
returns an MSB of 1.
If the Stale Data flag is not used, the MSB of the measurement value is always set to 0.
Using the count that is returned from channel 0 of the ulCInScan (or channel 0 of the counter
subsystem of the ulDaqInScan function), you can determine the following:• Frequency of a signal pulse (the number of periods per second). You can calculate thefrequency as follows: Frequency = 12 MHz/(Number of counts – 1)
where 12 MHz is the internal counter/timer clock frequency
For example, if the count is 21, the measured frequency is 600 kHz (12 MHz/20).
• Period of a signal pulse. You can calculate the period as follows: Period = 1/Frequency
 Period = (Number of counts – 1)/12 MHz
where 12 MHz is the internal counter/timer clock frequency

149

Appendix D

Phase Measurements – Tachometer Counter 1
On the DT9837A and DT9837B modules, you can measure the phase of the tachometer input
in relation to the A/D sample by using the ulCInScan function and specifying channel 1 or byusing the ulDaqInScan function and specifying channel number 1 and the counter channel
type in the DaqInChanDescriptor structure.
You can configure the settings for the measurement using the ulCtrSetConfig function withthe configItem CTR_CFG_REG. This configItem is used to write to General Control Register 4,
described in Table 38 on page 148. Specify the appropriate bitmask value for the register using
the configValue argument of the ulCtrSetConfig function. (You can first read the value of theregister using the ulCtrGetConfig function with the configItem CTR_CFG_REG to make thiseasier.)Note: The values that are set using ulCtrSetConfig are not retained in EEPROM; therefore,
they are not used at power up. It is recommended that your program initialize these values
when your program runs.

The following settings are configurable for tachometer counter 1 using configItem
CTR_CFG_REG and the ulCtrSetConfig function:• Tach Counter 1 Start Select (T1 ST, bit 15 and 14 of General Control Register 4) – To start
the measurement on the rising edge of the tachometer input signal, set bits 15 and 14 to avalue of 1 (Tach Input Rising Edge).
To start the measurement on the falling edge of the tachometer input signal, set bit 15 to avalue of 1 and bit 14 to a value of 0 (Tach Input Falling Edge).
To start the measurement on the falling edge of the A/D ready signal, set bits 15 and 14 toa value of 0 (A/D Ready Falling Edge).
• Tach Counter 1 Stop Select (T1 STP, bit 7 and 6 of General Control Register 4) – To stop themeasurement on the rising edge of the tachometer input signal, set bits 7 and 6 to a valueof 1 (Tach Input Rising Edge).
To stop the measurement on the falling edge of the tachometer input signal, set bit 7 to avalue of 1 and bit 6 to a value of 0 (Tach Input Falling Edge).
To stop the measurement on the falling edge of the A/D ready signal, set bits 7 and 6 to avalue of 0 (A/D Ready Falling Edge).

Note: If you choose to start the measurement using the A/D sample, choose atachometer edge to stop the measurement. Likewise, if you choose to stop themeasurement using the A/D sample, choose a tachometer edge to start the measurement.

• Tach Counter 1 Self Clear (T1 CLR, bit 4 of General Control Register 4) – Set bit 4 to a valueof 1 (Clear to 0 on write to Input FIFO) if you want to return a value of 0 between
measurements. Set bit 4 to a value of 0 (Keep the last value) if you want to return theprevious measurement value between readings.

150

Programming in Linux or macOS

Gate Measurements
In Windows, you can use the Open Layers Control panel to configure the settings that areused at power up for the gate input signal (gate counter 2) on the DT9837A-OEM andDT9837B modules. In UL for Linux, the DT9837A-OEM and DT9837B modules always power
up with the values for the gate input signal that were set through the Open Layers Control
Panel.
You can measure the phase of the gate input in relation to the A/D sample by using the
ulCInScan function and specifying channel 2 or by using the ulDaqInScan function andspecifying channel number 2 and the counter channel type in the DaqInChanDescriptor
structure.
You can configure the settings for the measurement using the ulCtrSetConfig function withthe configItem CTR_CFG_REG. This configItem is used to write to General Control Register 4,
described in Table 38 on page 148. Specify the appropriate bitmask value for the register using
the configValue argument of the ulCtrSetConfig function. (You can first read the value of theregister using the ulCtrGetConfig function with the configItem CTR_CFG_REG to make thiseasier.)Note: The values that are set using ulCtrSetConfig are not retained in EEPROM; therefore,
they are not used at power up. It is recommended that your program initialize these values
when your program runs.

The following settings are configurable for Gate Counter 2 using configItem CTR_CFG_REG
and the ulCtrSetConfig function:• Gate Counter 2 Start Select (G2 ST, bit 13 and 12 of General Control Register 4) – To start
the measurement on the rising edge of the gate input signal, set bits 13 and 12 to a value of
1 (Gate Input Rising Edge).
To start the measurement on the falling edge of the gate input signal, set bit 13 to a valueof 1 and bit 12 to a value of 0 (Gate Input Falling Edge).
To start the measurement on the falling edge of the A/D ready signal, set bits 13 and 12 toa value of 0 (A/D Ready Falling Edge).
• Gate Counter 2 Stop Select (G2 STP, bit 11 and 10 of General Control Register 4) – To stop
the measurement on the rising edge of the gate input signal, set bits 11 and 10 to a value of
1 (Gate Input Rising Edge).
To stop the measurement on the falling edge of the gate input signal, set bit 11 to a value of
1 and bit 10 to a value of 0 (Gate Input Falling Edge).
To stop the measurement on the falling edge of the A/D ready signal, set bits 11 and 10 toa value of 0 (A/D Ready Falling Edge).

151Appendix D

Note: If you choose to start the measurement using the A/D sample, choose a gate input
edge to stop the measurement. Likewise, if you choose to stop the measurement using theA/D sample, choose a gate input edge to start the measurement.
If you choose the start and stop the measurement using the same gate edge, you willmeasure the pulse width of the gate signal; be aware that the stopping edge does notrestart the measurement; the next starting edge will start the next measurement.

• Gate Counter 2 Self Clear (G2 CLR, bit 8 of General Control Register 4) – Set bit 8 to avalue of 1 (Clear to 0 on write to Input FIFO) if you want to return a value of 0 between
measurements.
Set bit 8 to a value of 0 (Keep the last value) if you want to return the previous
measurement value between readings.

Power Mode Setting
In Windows, the power mode setting is configured using the Open Layers Control Panel.
In UL for Linux, the DT9837A, DT9837B, or DT9837C module always powers up in low powermode, which helps to conserve power when the module is used with a laptop.
Once you run a UL for Linux program for the module, high power mode is turned on
automatically to ensure that the module is warmed up and that any settling time errors of the
IEPE current source are minimized. This setting is not configurable in UL for Linux.

Input Triggers
When using UL for Linux, acquisition starts when the input trigger occurs. Unlike DT-Open
Layers, a reference trigger is not used.
Users can monitor the data as it is being acquired to determine if a particular event (thresholdcrossing) has occurred.

Reading Back the Value of the Analog Output Channel
For the DT9837A only, you can read back the value of the analog output channel in the input
stream by using the ulDaqInScan function and specifying DAQI_DAC in the
DaqInChanDescriptor structure.

152

Programming in Linux or macOS

Synchronizing Acquisition on Multiple Modules
DT9837A, DT9837B, and DT9837C modules provide an RJ45 (LVDS) synchronization
connector that you can use to connect and synchronize multiple DT9837A, DT9837B, orDT9837C modules. In this scheme, one module is the master and the other modules are theslaves.

Notes: By default, no synchronization is used in UL for Linux. In this configuration, theDT9837A, DT9837B, or DT9837C module uses the USB clock instead of the RJ45
synchronization connector to provide the timebase for the clock.
When using the master/slave configuration, you can use DT9837A and DT9837B modules
together, however, the maximum sampling rate is limited by the slowest module (52.7 kHz, inthis case). If you are using DT9837C modules in a master/slave configuration, it isrecommended that you do not connect any other module type except the DT9837C.

To synchronize multiple modules using UL for Linux, do the following:• For the master device, set the options argument of the scan function that you want to use(ulAInScan, ulDaqInScan, or ulCInScan) to SO_TIMEBASEOUT. In this configuration,
the master outputs the clock signal (timebase) to the slave devices.
• For the slave devices, set the options argument of the scan function (ulAInScan,
ulDaqInScan, or ulCInScan) to SO_EXTTIMEBASE. In this configuration, the slave
devices accept the clock signal (timebase) from the master.
When the subsystem on the master is triggered, the subsystems on the master and theslave devices start acquiring data at the same time (within one A/D conversion of theclock). You can set the scan rate to be the same or different on each module.

Notes: If you are using multiple DT9837C modules and want to trigger the mastermodule with an analog threshold trigger, you must set the master and the slave devices to
use the analog threshold trigger for proper operation (no physical trigger connection to
the slave is required).
When you are finished acquiring data, be sure to stop the subsystems on the master andall connected slave modules before disconnecting the cable from the RJ45 connectors.

The synchronization settings remain set until changed or until the application exits.

153

Appendix D

154

IndexIndex
A
AC coupling 98
accessories 24, 87, 88
administrator privileges 36
aliasing 70
analog input
calibrating 114
channels 68
conversion modes 70
data format and transfer 74
error conditions 75
gain 68
IEPE functions 69
input range 68
resolution 69
sample clock 69
single-ended configuration 44
single-value operations 70
single-values operations 71
specifications 118
triggers 73
wiring 44
analog output
calibrating 116
channels 76
clock sources 76
continuous operations 78
conversion modes 77
data format and transfer 80
error conditions 81
gain 76
ranges 76
resolution 76
single-value operations 77
specifications 121
waveform generation mode 78
wiring 45
analog threshold trigger 73, 80
applet, Open Layers Control Panel 107
application wiring
analog inputs 44
analog output 45
gate input 47
tachometer input 46

applications
Quick DataAcq 23
QuickDAQ 21

Bbase clock frequency 101
BaseClockFrequency 101
binary data encoding 94
block diagrams
DT9837 64
DT9837A 65
DT9837B 66
DT9837C 67
buffers 94
inprocess flush 94
single wrap mode 94

C
C/C++ programs 23
cables, USB 33, 34
calibrating the module
analog input subsystem 114
analog output subsystem 116
running the calibration utility 113
CGLDepth 95
channel list
specifying a tachometer input 80
specifying gate counter 2 85
specifying tachometer counter 0 82
specifying tachometer counter 1 84, 150
channel type
differential 95
single-ended 95
channel-gain list depth 95
channels
analog input 68
analog output 76
number of 95
clocksanalog input 69
analog output 76
base frequency 101
internal 101
maximum external clock divider 101
maximum throughput 101

155

Index
minimum external clock divider 101
minimum throughput 101
simultaneous 101
connecting signals
analog inputs 44
analog output 45
gate input 47
tachometer input 46
connecting to the host computer 33
connector J1 pin assignments 134
connectors
Gate Input 133
RJ45 (LVDS) 129, 132
continuous analog input
post-trigger 93
continuous analog output 93
continuous counter/timer 93
continuous digital I/O 93
Control Panel applet 107
conversion modes
continuous analog output 78
single-value analog input 70
single-value analog output 77
single-values analog input 71
waveform generation mode 78
conversion rate 72
counter 0 82
counter 1 84, 150
counter 2 85
counter/timer 80
channels 95
clock sources 101
coupling type 69
current source 69, 98
customer service 109

D
DAQ Adaptor for MATLAB 23
data encoding 74, 80, 94
data flow modes
continuous C/T 93
continuous digital input 93
continuous post-trigger 93
single-value 93
waveform stored in FIFO only 93
data format and transfer
analog input 74
analog output 80
DataAcq SDK 23
DC coupling 98

156

device drivers 21, 36
Device Selection window 52
differential channels 95
digital trigger 73, 80
DT9837 Series Calibration Utility 21
DT-Open Layers for .NET Class Library 23

Eencoding data 74, 80
environmental specifications 127
EP386 panel 24, 87, 88
errorsanalog input 75
analog output 81
excitation current source 69
available 98
internal 98
expansion hub 34
external clock divider
maximum 101
minimum 101
external digital trigger 73, 80
positive TTL 99

F
factory service 109
features 14
FIFO 93
input 75, 93
output 78, 93
FifoSize 93
formatting data
analog input 74
analog output 80
frequency
analog input operations 69
base clock 101
internal A/D clock 101
internal A/D sample clock 101
internal C/T clock 101
internal retrigger clock 94

Ggain 68
actual available 95
analog output 76
number of 95
programmable 95

Indexgate input
counter 2 85
pin assignments 133
specifications 124, 129
wiring 47
group delay 70, 77

Hhardware features 14
hot-swapping 33

MaxRetriggerFreq 94
MaxSingleEndedChannels 95
MinExtClockDivider 101
MinFrequency 101
MinRetriggerFreq 94
multiple modules, triggering 86
muting the output voltage 78, 93

N

IEPE features 69
inprocess buffers 94
input
channels 68
configuration, single-ended 44
ranges 68
resolution 69
input FIFO 75, 93
internal clock 101
internal excitation current source 98

negative threshold trigger 100
number ofdifferential channels 95
gains 95
I/O channels 95
resolutions 96scans per trigger 94
single-ended channels 95
voltage ranges 96
NumberOfChannels 95
NumberOfRanges 96
NumberOfResolutions 96
NumberOfSupportedGains 95
Nyquist Theorem 70

JO

J1 connector pin assignments 134

Open Layers Control panel 36
Open Layers Control Panel applet 107
operation modes
single-value analog input 70
single-value analog output 77
single-values analog input 71
waveform generation 78
oscillator, specifications 126
outputclock sources 76
ranges 76
output FIFO 78, 93

I

L
LabVIEW 23
LED 33, 34
LED status indicator 134
legacy CPL elevated 36
Linux 23, 145
LVDS connector
pin assignments 132
specifications 129
LV-Link 23

M

macOS 23, 145
master device 53
master oscillator, specifications 126
MATLAB 23
MaxDifferentialChannels 95
MaxExtClockDivider 101
MaxFrequency 101
MaxMultiScanCount 94

Pphysical specifications 127
pin assignments 134
positive threshold trigger 99, 100
post-trigger acquisition mode 93
post-trigger scan count 100
power 34, 35
specifications 127
preparing to wire signals 41

157

IndexQ
Quick DataAcq application 23
QuickDAQ 51
Advanced FFT Analysis option 22
Base version 21
FFT Analysis option 22

Rrangesanalog input 68
analog output 76
number of 96
recommendations for wiring 41
reference trigger 74
register-level programming
DT9837 136
DT9837A 140
DT9837B 140
DT9837C 140
regulatory specifications 128
resolution
analog input 69
analog output 76
available 96
number of 96
retrigger clock frequency 94
returning boards to the factory 109
RJ45 connector
pin assignments 132
specifications 129
RMA 109

S
sample clock 69
scan count 100
SDK 23simultaneous clocking 101
simultaneous sample-and-hold support 95
single buffer wrap mode 94
single-ended channels 44, 95
number of 95
single-value configuration 70
single-value operations 93
analog output 77
single-values configuration 71
softwareLinux 23
macOS 23
Windows 21

158

software trigger 73, 80, 99
specifications 117
analog input 118
analog output 121
connector 129
environmental 127
gate input 124
master oscillator 126
physical 127
power 127
regulatory 128
tachometer input 123
triggers 125
start trigger 74
external digital (TTL) trigger 73
software 73
stopping an operation 72, 79
SupportedExcitationCurrentValues 98
SupportedGains 95
SupportedResolutions 96
SupportedThresholdTriggerChannel 99
SupportedThresholdTriggerChannels 100
SupportedVoltageRanges 96
SupportsACCoupling 98
SupportsBinaryEncoding 94
SupportsBuffering 94
SupportsContinuous 93
SupportsDCCoupling 98
SupportsDifferential 95
SupportsFallingEdge 103
SupportsInProcessFlush 94
SupportsInternalClock 101
SupportsInternalExcitationCurrentSrc 98
SupportsMute 93
SupportsNegThresholdTrigger 100
SupportsPosExternalTTLTrigger 99
SupportsPosThresholdTrigger 99, 100
SupportsPostTriggerScanCount 100
SupportsProgrammableGain 95
SupportsRisingEdge 103
SupportsSimultaneousClocking 101
SupportsSimultaneousSampleHold 95
SupportsSingleEnded 95
SupportsSingleValue 93
SupportsSoftwareTrigger 99
SupportsStaleDataFlag 103
SupportsSynchronization 93
SupportsWaveformModeOnly 93
SupportsWrapSingle 94
synchronization modes 93
SynchronizationMode 93

Indexsynchronizing tachometer and analog input data 70
system requirements 32

Ttachometer input 80, 82
counter 0 82
counter 1 84, 150
falling edges 103
rising edges 103
specifications 123
Stale Data flag 103
wiring 46
technical support 108
threshold trigger 80, 100channel 99
threshold trigger channels 100
threshold trigger, positive 99
throughput
maximum 101
minimum 101
trademark and copyright information 2transferring data
analog input 74
analog output 80
triggered scannumber of scans per trigger 94
retrigger frequency 94
triggering acquisition on multiple modules 86
triggers
analog input 73
analog threshold 80
analog threshold trigger 73
external 73, 80
external positive digital 99
negative threshold 100
positive analog threshold 99
positive threshold 100
software 73, 80, 99
specifications 125
threshold channel 100
troubleshooting
procedure 106
technical support 108
troubleshooting table 106
TTL trigger 73, 80

unmuting the output voltage 78, 93
unpacking 31
USB cable 33, 34
USB expansion hub 34

V
Visual Basic for .NET programs 23
Visual C# programs 23
voltage ranges 68, 96
number of 96

W
Windows software 21
wiring signals 41
analog inputs 44
analog output 45
gate input 47
preparing 41
recommendations 41
tachometer input 46
writing programs in
C/C++ 23
Visual Basic .NET 23
Visual C# 23

U
UL for Linux 146
Universal Library for Linux 146

159

Index160