USB-1808-OEM

Eight-Channel Simultaneous-Sampling Multifunction Device

User's Guide

May 2019. Rev 4© Measurement Computing Corporation

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Measurement Computing Corporation, InstaCal, Universal Library, and the Measurement Computing logo areeither trademarks or registered trademarks of Measurement Computing Corporation. Refer to the Copyrights &Trademarks section on mccdaq.com/legal for more information about Measurement Computing trademarks.
Other product and company names mentioned herein are trademarks or trade names of their respective
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 ininjury. Measurement Computing Corporation products are not designed with the components required, and are
not subject to the testing required to ensure a level of reliability suitable for the treatment and diagnosis ofpeople.

HM USB-1808-OEM.docx

2

Table of Contents
Preface

About this User's Guide ....................................................................................................................... 5
What you will learn from this user's guide ......................................................................................................... 5
Conventions in this user's guide ......................................................................................................................... 5
Where to find more information ......................................................................................................................... 5
Chapter 1

Introducing the USB-1808-OEM ........................................................................................................... 6
Functional block diagram ................................................................................................................................... 6
Chapter 2

Installing the USB-1808-OEM ............................................................................................................... 7
Unpacking........................................................................................................................................................... 7
Installing the software ........................................................................................................................................ 7
Installing the hardware ....................................................................................................................................... 7
Calibrating the hardware..................................................................................................................................... 7
Updating firmware .............................................................................................................................................. 7
Chapter 3

Functional Details ................................................................................................................................. 8
Board components .............................................................................................................................................. 8
USB connector .................................................................................................................................................................. 8
Header connectors............................................................................................................................................................. 9
LEDs ................................................................................................................................................................................10

Analog input ..................................................................................................................................................... 10
Channel-Gain queue ........................................................................................................................................................11

Analog output ................................................................................................................................................... 11
Digital I/O ......................................................................................................................................................... 11
Digital input scanning ......................................................................................................................................................11
Pull-up/down configuration .............................................................................................................................................12Counter input .................................................................................................................................................... 13
Totalize counter mode......................................................................................................................................................13
Period measurement mode ...............................................................................................................................................13
Pulse width measurement mode .......................................................................................................................................13

Quadrature encoder input ................................................................................................................................. 14
Timer output ..................................................................................................................................................... 14
Synchronous I/O – mixing analog, digital, and counter scanning .................................................................... 15
Clock I/O .......................................................................................................................................................... 15
Digital triggering .............................................................................................................................................. 15
Pattern triggering .............................................................................................................................................. 15
Mask option .....................................................................................................................................................................15

Ground .............................................................................................................................................................. 16
Power output ..................................................................................................................................................... 16
Mechanical drawings ........................................................................................................................................ 17
Chapter 4

Specifications ...................................................................................................................................... 18
Analog input ..................................................................................................................................................... 18
Accuracy ........................................................................................................................................................... 19
Analog input DC voltage measurement accuracy ............................................................................................................19
Dynamic performance ......................................................................................................................................................193

USB-1808-OEM User's Guide

Noise performance ...........................................................................................................................................................19

Analog output ................................................................................................................................................... 20
Analog input/output calibration ........................................................................................................................ 21
Digital input/output........................................................................................................................................... 21
Counter ............................................................................................................................................................. 22
Quadrature inputs.............................................................................................................................................................22

Timer ................................................................................................................................................................ 23
External clock input/output............................................................................................................................... 23
External trigger ................................................................................................................................................. 24
Pattern trigger ................................................................................................................................................... 24
Memory ............................................................................................................................................................ 24
Power ................................................................................................................................................................ 24
USB .................................................................................................................................................................. 25
Environmental .................................................................................................................................................. 25
Mechanical ....................................................................................................................................................... 25
Header connector .............................................................................................................................................. 25
Differential mode pinout ..................................................................................................................................................26
Single-ended mode pinout ...............................................................................................................................................27

EU Declaration of Conformity ............................................................................................................ 28

4

Preface

About this User's Guide
What you will learn from this user's guideThis user's guide describes the Measurement Computing USB-1808-OEM data acquisition device and lists
device specifications.

Conventions in this user's guide
For more information
Text presented in a box signifies additional information and helpful hints related to the subject matter you arereading.
Caution! Shaded caution statements present information to help you avoid injuring yourself and others,
damaging your hardware, or losing your data.
Bold text is used for the names of objects on a screen, such as buttons, text boxes, and checkboxes.

Italic text is used for the names of manuals and help topic titles, and to emphasize a word or phrase.

Where to find more information
Additional information about USB-1808-OEM hardware is available on our website at www.mccdaq.com. You
can also contact Measurement Computing Corporation with specific questions.


Knowledgebase: kb.mccdaq.com
Tech support form: www.mccdaq.com/support/support_form.aspx
Email: techsupport@mccdaq.com
Phone: 508-946-5100 and follow the instructions for reaching Tech Support

For international customers, contact your local distributor. Refer to the International Distributors section on our
web site at www.mccdaq.com/International.

5Chapter 1

Introducing the USB-1808-OEM
The USB-1808-OEM is a multifunction data acquisition device providing the following features:
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Eight 18-bit simultaneous-sampling differential (DIFF) or single-ended (SE) analog input channels –software-selectable per channel as DIFF or SE
Sample rate of 50 kS/s per channel maximum
Analog input ranges of ±10 V, ±5 V, 0 V to 10 V, and 0 V to 5 V – software-selectable per channel
Two 16-bit analog outputs
Four individually-configurable digital I/O channels
Two high-speed general-purpose counters
Two quadrature encoder inputs
Two timer outputs
One external digital trigger for data acquisition and one external digital trigger for data generation
Two external clock inputs and two clock outputs for synchronous input and output operations with morethan one device.
Header connectors for field wiring connections

The device is powered by the +5 V USB supply from the computer, requiring no external power.
The USB-1808-OEM is a USB 2.0 high-speed device that is fully compatible with both USB 1.1, USB 2.0, andUSB 3.0 ports.

Functional block diagram
USB-1808-OEM functions are illustrated in the block diagram shown here.

Figure 1. Functional block diagram

6

Chapter 2

Installing the USB-1808-OEM
UnpackingAs with any electronic device, you should take care while handling to avoid damage from static
electricity. Before removing the device from its packaging, ground yourself using a wrist strap or by simply
touching the computer chassis or other grounded object to eliminate any stored static charge.
Contact us immediately if any components are missing or damaged.

Installing the software
Refer to the USB-1808-OEM product page on our website for information about the software supported by theUSB-1808-OEM.
Install the software before you install your device
The driver needed to run the USB-1808-OEM is installed with the software. Therefore, you need to install thesoftware package you plan to use before you install the hardware.

Installing the hardware
To connect the USB-1808-OEM to your system, connect the USB cable to an available USB port on thecomputer or to an external USB hub connected to the computer. Connect the other end of the USB cable to the
USB connector on the device. No external power is required.
When connected for the first time, a Found New Hardware dialog opens when the operating system detects thedevice. When the dialog closes, the installation is complete. The Status LED on the USB-1808-OEM turns on
after the device is successfully installed.
If the Status LED turns off
If communication is lost between the device and the computer, the device LED turns off. To restore
communication, disconnect the USB cable from the computer and then reconnect it. This should restore
communication, and the LED should turn on.

Calibrating the hardware
The Measurement Computing Manufacturing Test department performs the initial factory calibration. Returnthe device to Measurement Computing Corporation when calibration is required. The recommended calibrationinterval is one year.

Updating firmware
Your DAQ device contains firmware that can be updated in the field if required. Firmware is available fordownload at www.mccdaq.com/firmware.aspx. MCC recommends that you check this page periodically to see
if an update to your device firmware is available.

7Chapter 3

Functional Details
Board components
USB-1808-OEM has the following components, as shown in Figure 2:Header connectors (2)Pull-up/down jumper
LED indicators (2)USB connector

Figure 2. USB-1808-OEM components
1
2
3

Header connector pins 1 to 28
Header connector pins 29 to 56
Pull-up/down jumper DIO

4
5

LED indicators (2)USB connector

USB connector
The USB connector provides +5 V power and communication. No external power supply is required.

8

USB-1808-OEM User's Guide

Functional Details

Header connectors
The header connectors provide the following connections:
Eight DIFF analog inputs (CH0H/CH0L to CH7H/CH7L) or eight SE analog inputs (CH0H to CH7H)
Refer to pages 9 and 10 for DIFF and SE pinouts.
Two analog outputs (AOUT0 and AOUT1)
Four digital I/O lines (DIO0 to DIO3)
Two general-purpose counter inputs (CTR0 and CTR1)
Two quadrature encoder inputs (ENC0A, ENC0B, ENC0Z and ENC1A, ENC1B, ENC1Z)
Two timer outputs (TMR0 and TMR1)
An external trigger input (ITRIG) and an external trigger output OTRIG)
Two external clock inputs (ICLKI and OCLKI) and two external clock outputs (ICLKO, OCLKO)
One +5 V power output (+VO) connection
Ten analog ground (AGND) and seven digital ground (GND) connections

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The USB-1808-OEM pinouts are shown below. Refer to Figure 2 on page 8.
Differential mode pinout
Pin
#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28

Label
CH0H
CH0L
AGND
CH1H
CH1L
AGND
CH2H
CH2L
AGND
CH3H
CH3L
AGND
+VO
AGND
GND
TMR0
TMR1
ICLKO
OCLKO
GND
ICLKI
OCLKI
ITRIG
OTRIG
GND
ENC1A
ENC1B
ENC1Z

Use
AI channel 0 HI
AI channel 0 LO
Analog groundAI channel 1 HI
AI channel 1 LO
Analog groundAI channel 2 HI
AI channel 2 LO
Analog groundAI channel 3 HI
AI channel 3 LO
Analog ground+5V power output
Analog ground
Digital Ground
Timer 0 output
Timer 1 output
Input scan clock output
Output scan clock output
Digital ground
Input scan clock input
Output scan clock input
Input Trigger
Output Trigger
Digital ground
Encoder 1 Input A
Encoder 1 Input B
Encoder 1 Input Z

Terminal
#
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56

9

Label
CH7L
CH7H
AGND
CH6L
CH6H
AGND
CH5L
CH5H
AGND
CH4L
CH4H
AGND
AOUT0
AOUT1
AGND
GND
DIO0
DIO1
GND
DIO2
DIO3
GND
CTR0
CTR1
GND
ENC0A
ENC0B
ENC0Z

Use
AI channel 7 LO
AI channel 7 HI
Analog groundAI channel 6 LO
AI channel 6 HI
Analog groundAI channel 5 LO
AI channel 5 HI
Analog groundAI channel 4 LO
AI channel 4 HI
Analog ground
AO channel 0
AO channel 1
Analog ground
Digital Ground
DIO channel 0
DIO channel 1
Digital Ground
DIO channel 2
DIO channel 3
Digital Ground
Counter 0 input
Counter 1 input
Digital ground
Encoder 0 Input A
Encoder 0 Input B
Encoder 0 Input Z

USB-1808-OEM User's Guide

Functional Details

Single-ended mode pinout
Terminal
#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28

Label
CH0H
NC
AGND
CH1H
NC
AGND
CH2H
NC
AGND
CH3H
NC
AGND
+VO
AGND
GND
TMR0
TMR1
ICLKO
OCLKO
GND
ICLKI
OCLKI
ITRIG
OTRIG
GND
ENC1A
ENC1B
ENC1Z

Use
AI channel 0 HI
No connection
Analog groundAI channel 1 HI
No connection
Analog groundAI channel 2 HI
No connection
Analog groundAI channel 3 HI
No connection
Analog ground+5V power output
Analog ground
Digital Ground
Timer 0 output
Timer 1 output
Input scan clock output
Output scan clock output
Digital ground
Input scan clock input
Output scan clock input
Input Trigger
Output Trigger
Digital ground
Encoder 1 Input A
Encoder 1 Input B
Encoder 1 Input Z

Terminal
#
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56

Label
NC
CH7H
AGND
NC
CH6H
AGND
NC
CH5H
AGND
NC
CH4H
AGND
AOUT0
AOUT1
AGND
GND
DIO0
DIO1
GND
DIO2
DIO3
GND
CTR0
CTR1
GND
ENC0A
ENC0B
ENC0Z

Use
No connection
AI channel 7 HI
Analog groundNo connection
AI channel 6 HI
Analog groundNo connection
AI channel 5 HI
Analog groundNo connection
AI channel 4 HI
Analog ground
AO channel 0
AO channel 1
Analog ground
Digital Ground
DIO channel 0
DIO channel 1
Digital Ground
DIO channel 2
DIO channel 3
Digital Ground
Counter 0 input
Counter 1 input
Digital ground
Encoder 0 Input A
Encoder 0 Input B
Encoder 0 Input Z

LEDs
The USB-1808-OEM has two LED indicators that indicate the status of power and data. The LEDs are stacked
one above the other (see Figure 2 on page 8).
The Status LED turns on when the device is detected by the computer.
The Activity LED blinks when data is transferred and is off otherwise.

Analog input
You can configure each analog input channel for either SE or DIFF mode. MCC recommends connecting
unused analog input terminals to analog ground terminals during operation. For example, if you are not using
CH7L, connect this terminal to an available AGND terminal.
The input voltage range is software-selectable per channel for ±10 V, ±5 V, 0 V to 10 V, or 0 V to 5 V.
Analog input operations can be paced by the internal clock or by an external clock (ICLKI – refer to Clock I/O
on page 15). They can be initiated by a digital trigger (Digital triggering on page 15) or a pattern trigger(Pattern triggering on page 15).
Refer to Synchronous I/O – mixing analog, digital, and counter scanning on page 15 for information on runninganalog input scans at the same time as other subsystem scans.
For more information about analog signal connections
For more information about analog input connections, refer to the Guide to DAQ Signal Connections (available
for download at www.mccdaq.com/support/DAQ-Signal-Connections.aspx).
10USB-1808-OEM User's Guide

Functional Details

Channel-Gain queue
The channel-gain queue feature allows you to configure a different gain setting for each channel. The gain
settings are stored in a channel-gain queue list that is written to local memory on the device.
The channel-gain queue list can contain up to eight unique elements. The channel list must be in increasingorder. An example of a five-element list is shown in the following table.
Sample channel-gain queue list
Element

Channel

Range

0
1
2
3
4

CH0H/CH0L (DIFF)
CH2H/AGND (SE)CH3H/AGND (SE)CH6H/CH6L (DIFF)
CH7H/CH7L (DIFF)

±10 V
±5 V
0 V to 5 V
0 V to 10 V
±5 V

Carefully match the gain to the expected voltage range on the associated channel or an over range condition
may occur. Although this condition does not damage the device, it does produce a useless full-scale reading,and can introduce a long recovery time due to saturation of the input channel.

Analog output
The two 16-bit analog outputs (AOUT0 and AOUT1) can be updated simultaneously at a rate of 250 kS/s perchannel. Each output can be updated at a rate of 250 kS/s. The output range is fixed at ±10 V. The outputs
default to 0 V at power up, or when a reset command is issued to the device.
Analog output operations can be paced by the internal clock or by an external clock (OCLKI – refer to Clock I/O
on page 15). They can be initiated by a digital trigger (Digital triggering on page 15) or a pattern trigger(Pattern triggering on page 15).
Refer to Synchronous I/O – mixing analog, digital, and counter scanning on page 15 for information on runninganalog output scans at the same time as other subsystem scans.

Digital I/O
You can connect up to four digital I/O lines to DIO0 through DIO3. Each digital channel is individuallyconfigurable for input or output. During initial power on or reset, the digital pins are set for input.
The digital I/O pins can detect the state of any TTL-level input. Refer to the schematic shown in Figure 3.

Figure 3. Schematic showing switch detection by digital channel DIO0

If you set the switch to the +5 V input, DIO0 reads TRUE (1). When set to GND, DIO0 reads FALSE (0).

Digital input scanning
Digital input operations can be paced by the internal clock or by an external clock (ICLKI – refer to Clock I/O
on page 15). They can be initiated by a digital trigger (Digital triggering on page 15) or a pattern trigger(Pattern triggering on page 24).
If no analog inputs are being scanned, the digital inputs can sustain rates up to 200 kHz. Digital input ports canalso be read asynchronously before, during, or after an analog input scan.
Refer to Synchronous I/O – mixing analog, digital, and counter scanning on page 15 for information on running
digital input scans at the same time as other subsystem scans.
11USB-1808-OEM User's Guide

Functional Details

Pull-up/down configuration
All digital I/O lines are pulled down to 0 V (LO) with a 47 kΩ resistor (default). You can change thepull-up/down configuration using the internal jumper labeled DIO. You must remove the device housing toaccess the jumper on the circuit board.
To set the jumper for pull-up or pull-down, complete the following steps.
1.

Unplug the device from the computer.

2.

Turn the device over and rest the top of the housing on a flat, stable surface.

Caution! The discharge of static electricity can damage some electronic components. Before removing theUSB-1808-OEM from its housing, ground yourself using a wrist strap or touch the computer
chassis or other grounded object to eliminate any stored static charge.
3.

Remove the rubber fee from the bottom of the device, and the four screws using a #1 Philips headscrewdriver.

4.

Hold both the top and bottom sections together, turn the device over and rest it on the surface, thencarefully remove the top section of the case to expose the circuit board.
Figure 4 shows the location of the DIO jumper on the circuit board.

Figure 4. Pull-up/down jumper location

5.

Configure the DIO jumper for pull-up or pull-down, as shown in Figure 5.

Figure 5. Pull-up/down jumper configuration

6.

Replace the top section of the housing and fasten it to the bottom section with the four screws.

For more information about digital signal connections
For general information about digital signal connections and digital I/O techniques, refer to the Guide to DAQ
Signal Connections (available for download at www.mccdaq.com/support/DAQ-Signal-Connections.aspx).
12

USB-1808-OEM User's Guide

Functional Details

Counter input
Counter inputs can be read asynchronously under program control, or synchronously as part of a digital scangroup.
The CTR0 and CTR1 pins are 32-bit general-purpose counters that can accept frequency inputs up to 50 MHz.
The USB-1808-OEM supports the following counter input modes:

Totalize
Period measurement
Pulse-width measurement

Counter input modes are programmable with software. Each mode supports additional counter operation
options.
Typically, when data is acquired with no counter operation options set, the count of each counter channel is set
to 0 and latched at the beginning of the acquisition.
When counter options are set the counters can concurrently monitor time periods, frequencies, pulses, and otherevent-driven incremental occurrences directly from pulse-generators, limit switches, proximity switches, andmagnetic pick-ups.
Counter input operations can be paced by the internal clock or by an external clock (ICLKI – refer to Clock I/O
on page 15). They can be initiated by a digital trigger (Digital triggering on page 15) or a pattern trigger(Pattern triggering on page 15).
Refer to Synchronous I/O – mixing analog, digital, and counter scanning on page 15 for information on runningcounter input scans at the same time as other subsystem scans.

Totalize counter mode
The USB-1808-OEM can be used as a high-speed pulse counter for general counting applications. The internalcounter increments when the TTL levels transition from low to high or from high to low.
Each option supported in Totalize mode is explained in following table:
Totalize counter mode options
Counter option

Description

Clear on read

The counter is cleared after each read (synchronous or asynchronous). The value of the counter
before it was cleared is latched and returned.
When counting up: The counter rolls over to MINLIMIT (or stops if Non-recycle is set) when the
maximum count (specified by the MAXLIMIT value) is reached.
When counting down: The counter counts down to MINLIMIT and then rolls over to MAXLIMIT(or stops if Non-recycle is set).
The counter stops if a count overflow or underflow occurs (or, if Range limit is set, the MAXLIMITor MINLIMIT value is reached). Counting resumes if direction is reversed or the counter is reloaded.

Range limit

Non-recycle

Period measurement modeUse period mode to measure the period of a signal at a counter channel's input. You can measure x1, x10, x100
or x1000 periods for 32-bit values. Four resolutions are available — 20 ns, 200 ns, 2000 ns, or 20,000 ns. All
period measurement mode options are software-selectable. The 100 MHz system clock is used as the timing
source. Periods from sub-microsecond to many seconds can be measured.

Pulse width measurement modeUse pulse width mode to measure the time from the rising edge to the falling edge, or vice versa, on a signal ona counter input. Four resolutions are available — 20 ns, 200 ns, 2000 ns, or 20,000 ns. All pulse width
measurement mode options are software selectable. The 100 MHz system clock is used as the timing source.
Pulse widths from sub-microsecond to many seconds can be measured.

13

USB-1808-OEM User's Guide

Functional Details

Quadrature encoder input
The USB-1808-OEM can simultaneously decode signals from up to two encoders. Quadrature encoders,
50 MHz maximum pulse frequency, and X1, X2, and X4 count modes are supported.
The USB-1808-OEM provides A, B, and Z inputs – ENCxA, ENCxB, and ENCxZ – for each connectedencoder. A typical encoder generates the A and B signals at a 90° phase shift with respect to each other. Thesesignals are used to determine system position (counts), velocity (counts per second), and direction of travel orrotation. The Z signal can be programmed to latch the current count or reload the counter with the MINLIMIT
value (counting up) or the MAXLIMIT value (counting down).
The Z signal may be used to establish an absolute reference position within one count of the encoder travel orrotation. This signal can be used to reload the position counter, which is useful at system startup when theincremental encoder cannot determine the starting position.
Encoder input operations can be paced by the internal clock or by an external clock (ICLKI – refer to Clock I/O
on page 15). They can be initiated by a digital trigger (Digital triggering on page 15) or a pattern trigger(Pattern triggering on page 15).
Refer to Synchronous I/O – mixing analog, digital, and counter scanning on page 15 for information on running
quadrature encoder scans at the same time as other subsystem scans.
Each supported quadrature encoder option is explained in following table:
Quadrature encoder options
Encoder
optionDescription

Count mode

Select X1, X2, or X4. Count modes provide different levels of accuracy with respect to the encoder
position.
 X1: counts rising edges on input A.
 X2: counts rising edges and falling edges on input A.
 X4: count rising and falling edges on both inputs A and B.
When counting up: The counter stops when the maximum count (specified by the MAXLIMIT
value) is reached. Counting resumes if direction is reversed or the counter is cleared.
When counting down: The counter stops when the minimum count (specified by the MINLIMIT
value) is reached. Counting resumes if direction is reversed or the counter is cleared.

Range limit

Quadrature encoder options that are specific to the Z signal (ENCxZ) are is explained in following table.
Z input quadrature encoder options ()Counter mode

Description

Clear on Z
Latching

The counter is cleared by the Z signal.
Latching mode allows the count to be latched by the Z signal.

Timer output
You can use TMR0 through TMR1 as 32-bit timer outputs. Each timer can generate pulse rates of up to 50 MHz,
with programmable pulse widths down to 10 ns.
The timer output rate and pulse width can be updated asynchronously at any time, however, doing so results in apulse stream that is not seamless.
The following timer output options are software-selectable:

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

pulse frequency
duty cycle (pulse width divided by the pulse period)
number of pulses to generate
time delay before starting the timer output after it is enabled
idle state of the output (idle high or idle low)

The time delay can range from 0 seconds to 42.94 seconds.
14USB-1808-OEM User's Guide

Functional Details

Figure 6. USB-1808-OEM PWM timer channel

Timer output operations can be paced by the internal clock or by an external clock (OCLKI – refer to Clock I/O
below). They can be initiated by a digital trigger (Digital triggering below).

Synchronous I/O – mixing analog, digital, and counter scanning
The USB-1808-OEM can read analog, digital, and counter inputs, and generate up to two analog outputs andone digital pattern output at the same time. Digital and counter inputs do not affect the overall A/D rate because
these inputs use no time slot in the scanning sequencer.
For example, one analog input channel can be scanned at the full 50 kS/s A/D rate along with digital andcounter input channels. Each analog channel can have a different gain, and counter and digital channels do notneed additional scanning bandwidth if there is at least one analog channel in the scan group. Digital input
channel sampling is done during the dead time of the scan period when no analog sampling is being done.

Clock I/O
The USB-1808-OEM provides one external clock input (ICLKI) and one clock output (ICLKO) for input
operations.
Connect an external clock signal to ICLKI.
The pacer clock is available at ICLKO.

The USB-1808-OEM provides one external clock input (OCLKI) and one clock output (OCLKO) for output
operations.
Connect an external clock signal to OCLKI.
The pacer clock is available at OCLKO.

Digital triggering
The ITRIG (for triggering input operations) and OTRIG (for triggering output operations) pins are external
digital trigger inputs. The trigger mode is software-selectable for edge or level sensitive. Edge sensitive mode isselectable for rising or falling. Level sensitive mode is selectable for high or low.

Pattern triggering
You can also start an input or output scan with a digital pattern trigger using DIO0 – DIO3. The patternrepresents the state of up to four bits on the port.
You specify the pattern and the trigger type with software. Supported trigger types are Above Pattern, Below
Pattern, Equal Pattern, and Not Equal Pattern. The scan begins when the trigger conditions are met.
The base clock is fixed at 100 MHz (10 ns). The trigger pattern must be held for five base clock cycles (50 ns)
to ensure that it is properly detected. The trigger latency is 1 scan clock period + 8 base clock cycles (80 ns).

Mask option
Use a bitmask to specify which bits to include or exclude from the pattern to detect. To include a bit in thepattern, sets its value to 1. To exclude a bit from the pattern, sets its value to 0. Refer to the pattern and mask
values shown in Figure 7 and Figure 8.
15

USB-1808-OEM User's Guide

Functional Details

In Figure 7 all mask bits are set to 1, so all the bits are included in the pattern to detect.

Figure 7. Trigger mask with all bits included

In Figure 8 all mask bits are excluded except bit 3. The result of this operation is that only bit 3 is included in
the pattern to detect.

Figure 8. Trigger mask with some bits excluded

GroundThe analog ground (AGND) pins provide a common ground for all analog channels.
The digital ground (GND) pins provide a common ground for the digital, trigger, counter, and encoder pins.

Power output
The +VO pin can output up to 10 mA maximum. You can use this pin to supply power to external devices or
circuitry.

16

USB-1808-OEM User's Guide

Functional Details

Mechanical drawings

Figure 9. USB-1808-OEM circuit board dimensions

17

Chapter 4

Specifications
All specifications are subject to change without notice.
Typical for 25 °C unless otherwise specified.
Specifications in italic text are guaranteed by design.

Analog input
Table 1. General analog input specifications
Parameter

Condition

Specification

A/D converter type
ADC resolution

Simultaneous
18 bits

Number of channels

8 differential (DIFF), 8 single-ended (SE);software-selectable per-channel for SE or DIFF
±10 V, ±5 V, 0 V to 10 V, 0 V to 5 V
Software-selectable per channel
 ±25 V max (power on)
 ±15 V max (power off) >1 GΩ (power on)
 1000 Ω (power off)
±50 pA
2.0 MHz

Input voltage range
Absolute max input voltage

CHx relative to AGND

Input impedance
Input bias current
Input bandwidth
Input capacitanceCommon mode voltage
range

Common mode rejection
ratio
CrosstalkAll input ranges, small signal(–3 dB)±10 V range±5 V range
0 V to 10 V range
0 V to 5 V range
fIN ≤ 1 kHz, all input ranges±10 V, adjacent channels,
DC to 100 kHz

Input coupling
Sample rate
Scan clock source–95 dBDC
0.023 Hz to 50 kHz; software-selectable
Internal input scan clock or external input scanclock (ICLKI pin)
 ITRIG (see External trigger on page 24)
 Digital pattern detection (see Pattern trigger on
page 24)
Software-selectable. Queue list may contain up to
eight elements of unique, consecutive channels
paired with any valid range.
15 minutes min

Trigger source

Channel gain queue

50 pf±10.1 V
±10.1 V
±10.1 V
±10.1 V
90 dB

Up to 8 elements

Warm-up time18USB-1808-OEM User's Guide

Specifications

Accuracy
Analog input DC voltage measurement accuracy
Table 2. DC accuracy components and specifications. All values are (±)

Range

Gain error(% ofreading)

Offset error
(mV)

±10 V
±5 V
0 V to 10 V
0 V to 5 V

0.020
0.020
0.020
0.020

1.5
1.0
1.5
1.0

INL error(% of range)

Absolute
accuracy at
Full Scale
(mV)

Gain
temperature
coefficient(% reading/°C)

Offsettemperature
coefficient(µV/°C)

0.000760.00057
0.000280.00014

3.576
2.028
3.528
2.007

0.000230.000230.000230.00023

4
4
4
4

Dynamic performance
Table 3. Dynamic performance specifications
Range

±10 V

±5 V

0 V to 10 V

0 V to 5 V

Condition

Specification

Signal-to-noise ratio (SNR)
Signal-to-noise-and-distortion ratio(SINAD)
Total harmonic distortion (THD)
Spurious free dynamic range (SFDR)
Effective number of bits (ENOB)
SNR
SINAD
THD
SFDR
ENOB
SNR
SINAD
THD
SFDR
ENOB
SNR
SINAD
THD
SFDR
ENOB

94 dB
94 dB
–108 dB
112 dB
15.3 bits
91 dB
91 dB
–105 dB
107 dB
14.8 bits
87 dB
87 dB
–104 dB
109 dB
14.5 bits
83 dB
83 dB
–103 dB
103 dB
13.6 bits

Noise performance
For the peak-to-peak noise distribution test, a differential input channel is connected to AGND at the input
terminal block, and 32,000 samples are acquired at the maximum rate available at each setting.
Table 4. Noise performance specifications
Range

Counts

LSBrms±10 V±5 V
0 V to 10 V
0 V to 5 V

11.6
18.0
23.3
36.1

1.77
2.73
3.54
5.47

19

USB-1808-OEM User's Guide

Specifications

Analog output
Table 5. Analog output specifications
Parameter

Condition

Number of channels
Resolution
Output ranges
Output transientSpecification

Calibrated
Host computer is reset, powered on,
suspended, or a reset command is issued
to the device
Powered off from 0 V output

Differential non-linearity
Output current
Output short-circuit protection

AOUTx pins
Single AOUTx channel connected to
AGND

Output couplingPower on and reset stateOutput noise
Trigger source

Note 1:
Note 2:

Duration: 20 ms
Amplitude: 5 V p-p±0.25 LSB typ±1 LSB max±3.5 mA max
Unlimited duration
DC
DACs cleared to zero-scale: 0 V, ±50 mV
100 µVrms
 OTRIG (see External trigger on page24)
 Digital pattern detection (see Pattern
trigger on page 24)
Internal output scan clock or external
output scan clock (OCLKI pin)
0.023 Hz to 125 kHz per channel
15 V/µS
33 S/s to 8,000 S/s typ, system-dependent
250 kS/s max, system-dependent

Scan clock source
Output update rate
Slew rate
Throughput

2
16 bits±10 V
Duration: 5 ms
Amplitude: 2 V p-p

Software paced
Hardware paced

Leave unused AOUTx output channels disconnected.
AOUTx defaults to 0 V whenever the host computer is reset, powered on, suspended, or a reset command isissued to the device.
Table 6. Calibrated absolute accuracy specifications

Range

Absolute accuracy (±LSB)

±10 V

16
Table 7. Calibrated absolute accuracy components specifications

Range

% of
reading

Offset(±mV)

Offset tempco(µV/°C)

Gain tempco(ppm of range/°C)±10 V

0.0183

1.831

4.7

9.4

Table 8. Relative accuracy specifications (±LSB)
Range

Relative accuracy (INL)

±10 V

1.0

20

USB-1808-OEM User's Guide

Specifications

Analog input/output calibration
Table 9. Analog I/O calibration specifications
Parameter

Specification

Warm-up time
Calibration method
Calibration interval

15 minutes recommended min
Factory calibration
1 yearDigital input/output
Table 10. Digital I/O specifications
Parameter

Specification

Digital type
Number of I/O
Configuration
Pull-up configuration

CMOS
4
Each bit may be configured as input (power on default) or output
The port has 47 kΩ resistors configurable as pull-up or pull-down (default) via internal
jumper (DIO).
33 to 8,000 port reads/writes or single bit reads/writes per second typ,system dependent.
0.023 Hz to 50 kHz input, 125 kHz output, based on the internal clock speed of
100 MHz
Internal input scan clock or external input scan clock (ICLKI pin)Internal output scan clock or external output scan clock (OCLKI pin)
 ITRIG for inputs, OTRIG for outputs (see External trigger on page 24)
 Digital pattern detection for inputs and outputs (see Pattern trigger on page 24)
2.0 V min
5.5 V absolute max
0.8 V max
–0.5 V absolute min
0 V recommended min
4.4 V min (IOH = –50 µA)
3.76 V min (IOH = –2.5 mA)
0.1 V max (IOL = 50 µA)
0.44 V max (IOL = 2.5 mA)±2.5 mA max

Digital I/O transfer rate(system-paced, asynchronous)
Digital I/O transfer rate
(synchronous)
Scan clock source for input
Scan clock source for input
Trigger source
Input high voltage
Input low voltage

Output high voltage
Output low voltage
Output current

21

USB-1808-OEM User's Guide

Specifications

CounterTable 11. Counter specifications
Parameter

Specification

Terminal names
Number of channels
Resolution
Counter typeCounter input modes
Input type
Input source

CTR0, CTR1
2 channels
32-bitFPGA
Totalize, Pulse width, Period
Schmitt trigger, 33 Ω series resistor, 47 kΩ pull-down to ground
CTR0
CTR1
Internal input scan clock or external input scan clock (ICLKI pin)
 ITRIG (see External trigger on page 24)
 Digital pattern detection (see Pattern trigger on page 24)
Internal or external input scan clock up to 50 kHz

Scan clock source
Trigger source
Counter read clock
Period/pulse width resolution
Input high voltage
Input low voltage
Schmitt trigger hysteresis
Input frequency
Schmitt trigger hysteresis

Input high voltage threshold

Input low voltage threshold

Input low voltage limit

20 ns, 200 ns, 2 µs or 20 µs; software-selectable
2.2 V min, 5.5 V max
1.5 V max, –0.5 V min
0.4 V min, 1.2 V max
50 MHz, max
0.76 V typ
0.4 V min
1.2 V max
1.74 V typ
1.3 V min2.2 V max
0.98 V typ
0.6 V min
1.5 V max
–0.5 V absolute min
0 V recommended min

Quadrature inputs
Table 12. Quadrature input specifications
Parameter

Specification

Terminal names
Number of encoders
Signals per encoder
Resolution
Maximum frequency
Minimum pulse widthDe-bounce function
Scan clock source
Trigger source

ENC0A, ENC0B, ENC0Z; ENC1A, ENC1B, ENC1Z
2
A, B and Z
20 ns
50 MHz
10 ns
NoneInternal input scan clock or external input scan clock (ICLKI pin)
 ITRIG (see External trigger on page 24)
 Digital pattern detection (see Pattern trigger on page 24)
2.2 V min, 5.5 V max
1.5 V max, –0.5 V min
5.5 V

Input high voltage
Input low voltage
Absolute maximum input
voltage22

USB-1808-OEM User's Guide

Specifications

Timer
Table 13. Timer specifications
Parameter

Specification

Terminal nameTimer typeOutput value
Trigger source
Internal clock frequency
Register widths
High pulse width
Low pulse width
Output high voltage

TMR0, TMR1
PWM output with count, period, delay, and pulse width registers
Default state is idle low with pulses high, software-selectable output invert
OTRIG (see External trigger on page 24)
100 MHz
32-bit
10 ns min
10 ns min
4.4 V min (IOH = –50 µA)
3.76 V min (IOH = –2.5 mA)
0.1 V max (IOL = 50 µA)
0.44 V max (IOL = 2.5 mA)±2.5 mA max

Output low voltage
Output current

External clock input/output
Table 14. External clock I/O specifications
Parameter

Specification

Terminal names

ICLKI, ICLKOOCLKI, OCLKOxCLKI:
Input, active on rising edge
xCLKO:
Output, power on default is 0 V, active on rising edge
xCLKI:
Receives sampling clock from external source
xCLKO:
Outputs the internal input scan or internal output scan clock, or thepulse generated from xCLKI when in external clock mode.
125 kHz max
xCLKI:
400 ns min
xCLKO:
400 ns min
Schmitt trigger, 33 Ω series resistor, 47 kΩ pull-down to ground
0.4 V to 1.2 V
2.2 V min
5.5 V absolute max
1.5 V max
–0.5 V absolute min
0 V recommended min
4.4 V min (IOH = –50 µA)
3.76 V min (IOH = –2.5 mA)
0.1 V max (IOL = 50 µA)
0.44 V max (IOL = 2.5 mA)±2.5 mA max

Terminal types
Terminal descriptions

Input clock rate
Clock pulse width
Input type
Schmitt trigger hysteresis
Input high voltage
Input low voltage

Output high voltage
Output low voltage
Output current

23

USB-1808-OEM User's Guide

Specifications

External trigger
Table 15. External trigger specifications
Parameter

Specification

Trigger source
Trigger mode

ITRIG for inputs, OTRIG for outputs
Software programmable for edge or level sensitive, rising or falling edge, high or low
level. Power on default is edge sensitive, rising edge.
1 µs + 1 clock cycle max
100 ns min
Schmitt trigger, 33 Ω series resistor and 49.9 kΩ pull-down to ground
0.4 V to 1.2 V
2.2 V min
5.5 V absolute max
1.5 V max
–0.5 V absolute min
0 V recommended min

Trigger latency
Trigger pulse width
Input type
Schmitt trigger hysteresis
Input high voltage
Input low voltage

Pattern trigger
Table 16. Pattern trigger specifications
Parameter

Specification

Trigger source
Trigger types
Trigger stability
Trigger bit width
Trigger latency

DIO0 – DIO3
Above pattern, Below pattern, Equal pattern, or Not equal pattern
Digital port must be stable for 50 ns to be recognized as a pattern
Up to 4, adjustable through bitmask
Up to 1 scan period

MemoryTable 17. Memory specifications
Parameter

Specification

Data FIFO
Non-volatile memory

4 kS analog input/2 kS analog output
32 KB (28 KB firmware storage, 4 KB calibration/user data)

Power
Table 18. Power specifications
Parameter

Condition

Specification

Supply current (Note 3)+VO user output voltage range(Note 4)+VO user output current

Quiescent current
Available at connector pin 13

305 mA
4.5 V min to 5.25 V max

Available at connecter pin 13

10 mA max

Note 3:Note 4:This is the total quiescent current requirement for the device that includes up to 10 mA for the status LED. This
does not include any potential loading of the digital I/O bits, +VO terminal, or the AOUTx outputs.
The +4.5 V min limit includes the +VO 10 mA load, it does not include any potential loading of the digital I/O
bits or the AOUTx outputs.

24USB-1808-OEM User's Guide

Specifications

USB
Table 19. USB specifications
Parameter

Specification

USB device type
Device compatibility
USB cable type

USB 2.0 (high-speed)
USB 1.1, USB 2.0, USB 3.0
A-B cable, UL type AWM 2725 or equivalent. (Min 24 AWG VBUS/GND,
min 28 AWG D+/D–)
3 m (9.84 ft) max

USB cable length

Environmental
Table 20. Environmental specifications
Parameter

Specification

Operating temperature range
Storage temperature range
Humidity

0 °C to 55 °C max–40 °C to 85 °C max
0% to 90% non-condensing max

Mechanical
Table 21. Mechanical specifications
Parameter

Specification

Dimensions (L × W × H)User connection length

119.38 × 86.36 × 1.57 (4.7 × 3.4 × 0.062 in.)3 m (9.84 ft) max

Header connector
Table 22. Header connector specifications
Parameter

Specification

Connector type
Wire gauge range

Two 1 × 28 pin 0.1 in. pitch headers
16 AWG to 30 AWG

25

USB-1808-OEM User's Guide

Specifications

Differential mode pinout
Table 23. 8-channel differential mode pinout
Terminal
#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28

Label
CH0H
CH0L
AGND
CH1H
CH1L
AGND
CH2H
CH2L
AGND
CH3H
CH3L
AGND
+VO
AGND
GND
TMR0
TMR1
ICLKO
OCLKO
GND
ICLKI
OCLKI
ITRIG
OTRIG
GND
ENC1A
ENC1B
ENC1Z

Use
AI channel 0 HI
AI channel 0 LO
Analog groundAI channel 1 HI
AI channel 1 LO
Analog groundAI channel 2 HI
AI channel 2 LO
Analog groundAI channel 3 HI
AI channel 3 LO
Analog ground+5V power output
Analog ground
Digital Ground
Timer 0 output
Timer 1 output
Input scan clock output
Output scan clock output
Digital ground
Input scan clock input
Output scan clock input
Input Trigger
Output Trigger
Digital ground
Encoder 1 Input A
Encoder 1 Input B
Encoder 1 Input Z

Terminal
#
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56

26

Label
CH7L
CH7H
AGND
CH6L
CH6H
AGND
CH5L
CH5H
AGND
CH4L
CH4H
AGND
AOUT0
AOUT1
AGND
GND
DIO0
DIO1
GND
DIO2
DIO3
GND
CTR0
CTR1
GND
ENC0A
ENC0B
ENC0Z

Use
AI channel 7 LO
AI channel 7 HI
Analog groundAI channel 6 LO
AI channel 6 HI
Analog groundAI channel 5 LO
AI channel 5 HI
Analog groundAI channel 4 LO
AI channel 4 HI
Analog ground
AO channel 0
AO channel 1
Analog ground
Digital Ground
DIO channel 0
DIO channel 1
Digital Ground
DIO channel 2
DIO channel 3
Digital Ground
Counter 0 input
Counter 1 input
Digital ground
Encoder 0 Input A
Encoder 0 Input B
Encoder 0 Input Z

USB-1808-OEM User's Guide

Specifications

Single-ended mode pinout
Table 24. 16-channel single-ended mode pinout
Terminal
#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28

Label
CH0H
NC
AGND
CH1H
NC
AGND
CH2H
NC
AGND
CH3H
NC
AGND
+VO
AGND
GND
TMR0
TMR1
ICLKO
OCLKO
GND
ICLKI
OCLKI
ITRIG
OTRIG
GND
ENC1A
ENC1B
ENC1Z

Use
AI channel 0 HI
No connection
Analog groundAI channel 1 HI
No connection
Analog groundAI channel 2 HI
No connection
Analog groundAI channel 3 HI
No connection
Analog ground+5V power output
Analog ground
Digital Ground
Timer 0 output
Timer 1 output
Input scan clock output
Output scan clock output
Digital ground
Input scan clock input
Output scan clock input
Input Trigger
Output Trigger
Digital ground
Encoder 1 Input A
Encoder 1 Input B
Encoder 1 Input Z

Terminal
#
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56

27

Label
NC
CH7H
AGND
NC
CH6H
AGND
NC
CH5H
AGND
NC
CH4H
AGND
AOUT0
AOUT1
AGND
GND
DIO0
DIO1
GND
DIO2
DIO3
GND
CTR0
CTR1
GND
ENC0A
ENC0B
ENC0Z

Use
No connection
AI channel 7 HI
Analog groundNo connection
AI channel 6 HI
Analog groundNo connection
AI channel 5 HI
Analog groundNo connection
AI channel 4 HI
Analog ground
AO channel 0
AO channel 1
Analog ground
Digital Ground
DIO channel 0
DIO channel 1
Digital Ground
DIO channel 2
DIO channel 3
Digital Ground
Counter 0 input
Counter 1 input
Digital ground
Encoder 0 Input A
Encoder 0 Input B
Encoder 0 Input Z

EU Declaration of Conformity
According to ISO/IEC 17050-1:2010
Manufacturer:
Address:

Product Category:
Date and Place of Issue:
Test Report Number:

Measurement Computing Corporation
10 Commerce Way
Norton, MA 02766
USAElectrical equipment for measurement, control and laboratory use.
March 23, 2017, Norton, Massachusetts USA
EMI6990.17

Measurement Computing Corporation declares under sole responsibility that the productUSB-1808-OEM
is in conformity with the relevant Union Harmonization Legislation and complies with the essential
requirements of the following applicable European Directives:
Electromagnetic Compatibility (EMC) Directive 2014/30/EU
Low Voltage Directive 2014/35/EU
RoHS Directive 2011/65/EU
Conformity is assessed in accordance to the following standards:
EMC:
Emissions: EN 61326-1:2013 (IEC 61326-1:2012), Class A
 EN 55011: 2009 + A1:2010 (IEC CISPR 11:2009 + A1:2010), Group 1, Class A
Immunity: EN 61326-1:2013 (IEC 61326-1:2012), Controlled EM Environments EN 61000-4-2:2008 (IEC 61000-4-2:2008)
 EN 61000-4-3 :2010 (IEC61000-4-3:2010)
Safety: EN 61010-1 (IEC 61010-1)
Environmental Affairs:
Articles manufactured on or after the Date of Issue of this Declaration of Conformity do not contain any of therestricted substances in concentrations/applications not permitted by the RoHS Directive.

Carl Haapaoja, Director of Quality Assurance

Measurement Computing Corporation
10 Commerce Way
Norton, Massachusetts 02766(508) 946-5100
Fax: (508) 946-9500
E-mail: info@mccdaq.com
www.mccdaq.com

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Phone: +36 (52) 515400
Fax: +36 (52) 515414
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