WLS-TEMP
Wireless Sensor Measurement

User's Guide

Document Revision 5A
March 2013
© Copyright 2013

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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.
© 2014 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 WLS-TEMP.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 WLS-TEMP .................................................................................................................. 6
Overview: WLS-TEMP features ........................................................................................................................ 6
Remote wireless operation ................................................................................................................................................ 6

WLS-TEMP block diagram ................................................................................................................................ 7
Chapter 2

Installing the WLS-TEMP ...................................................................................................................... 8
What comes with your shipment? ....................................................................................................................... 8
Hardware .......................................................................................................................................................................... 8
Documentation .................................................................................................................................................................. 8

Unpacking........................................................................................................................................................... 8
Installing the software ........................................................................................................................................ 8
Installing the hardware ....................................................................................................................................... 8
Configuring the hardware ................................................................................................................................... 9
Temperature sensors ......................................................................................................................................................... 9
Network parameters (remote operation) ..........................................................................................................................10

Connecting the external power supply for remote operation ............................................................................ 11
Calibrating the WLS-TEMP ............................................................................................................................. 11
Warm up time ................................................................................................................................................... 11
Chapter 3

Sensor Connections ...........................................................................................................................12
Screw terminal pinout ....................................................................................................................................... 12
Sensor input .....................................................................................................................................................................12
Current excitation output .................................................................................................................................................13
Four-wire, two sensor common .......................................................................................................................................13
Two sensor common ........................................................................................................................................................13
CJC sensors......................................................................................................................................................................13
Digital I/O ........................................................................................................................................................................13
Power output ....................................................................................................................................................................13
Ground .............................................................................................................................................................................13

Thermocouple connections ............................................................................................................................... 13
Wiring configuration........................................................................................................................................................14

RTD and thermistor connections ...................................................................................................................... 14
Two-wire configuration ...................................................................................................................................................15
Three-wire configuration .................................................................................................................................................16
Four-wire configuration ...................................................................................................................................................16

Semiconductor sensor measurements ............................................................................................................... 17
Wiring configuration........................................................................................................................................................17

Digital I/O connections ..................................................................................................................................... 17
Configuring the DIO channels to generate alarms ...........................................................................................................18
Chapter 4

Functional Details ...............................................................................................................................19
Thermocouple measurements ........................................................................................................................... 19
Cold junction compensation (CJC) ..................................................................................................................................19
Data linearization .............................................................................................................................................................193

WLS-TEMP Specifications

Open-thermocouple detection (OTD) ..............................................................................................................................19

RTD and thermistor measurements .................................................................................................................. 20
Data linearization .............................................................................................................................................................20

AC power supply .............................................................................................................................................. 20
External components ........................................................................................................................................ 20
Screw terminals................................................................................................................................................................21
USB connector .................................................................................................................................................................21
Status LEDs .....................................................................................................................................................................21
LED Test button...............................................................................................................................................................22
Chapter 5

Specifications ......................................................................................................................................23
Analog input ..................................................................................................................................................... 23
Channel configurations ..................................................................................................................................... 24
Compatible sensors ........................................................................................................................................... 24
Accuracy ........................................................................................................................................................... 25
Thermocouple measurement accuracy .............................................................................................................................25
Semiconductor sensor measurement accuracy .................................................................................................................25
RTD measurement accuracy ............................................................................................................................................26
Thermistor measurement accuracy ..................................................................................................................................26

Throughput rate to PC (USB or wireless) ......................................................................................................... 27
Digital input/output........................................................................................................................................... 27
Temperature alarms .......................................................................................................................................... 28
Memory ............................................................................................................................................................ 28
Microcontroller ................................................................................................................................................. 28
Wireless communications ................................................................................................................................. 28
USB +5V voltage ............................................................................................................................................. 29
Power ................................................................................................................................................................ 29
USB specifications ........................................................................................................................................... 30
Current excitation outputs (Ix+) ....................................................................................................................... 30
Environmental .................................................................................................................................................. 30
Mechanical ....................................................................................................................................................... 30
LED / button configuration ............................................................................................................................... 31
Screw terminal connector ................................................................................................................................. 32
Declaration of Conformity ..................................................................................................................33

4

Preface

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

Conventions in this user's guide
For more information
Text presented in a box signifies additional information related to the subject matter.
Caution! Shaded caution statements present information to help you avoid injuring yourself and others,
damaging your hardware, or losing your data.
bold text

Bold text is used for the names of objects on a screen, such as buttons, text boxes, and check boxes.

italic text

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 WEB-TEMP hardware is available on our website at www.mccdaq.com. You canalso contact Measurement Computing Corporation with specific questions.


Knowledgebase: kb.mccdaq.com
Phone: 508-946-5100 and follow the instructions for reaching Tech Support
Fax: 508-946-9500 to the attention of Tech Support
Email: techsupport@mccdaq.com

5Chapter 1

Introducing the WLS-TEMP
Overview: WLS-TEMP features
This user's guide contains all of the information you need to configure the WLS-TEMP for remote wirelessoperation, and to connect to the signals you want to measure.
The WLS-TEMP is a wireless-based USB 2.0 full-speed temperature measurement module that is supported
under popular Microsoft® Windows® operating systems. The WLS-TEMP is fully compatible with both
USB 1.1 and USB 2.0 ports.
The WLS-TEMP provides eight differential input channels that are software programmable for different sensor
categories including thermocouple, RTD, thermistor and Semiconductor sensors. Eight independent, TTLcompatible digital I/O channels are provided to monitor TTL-level inputs, communicate with external devices,and to generate alarms. The digital I/O channels are software programmable for input or output.
You can take measurements from four sensor categories:

Thermocouple – types J, K, R, S, T, N, E, and B
Resistance temperature detectors (RTDs) – two, three, or four-wire measurements of 100 Ω platinum RTDs
Thermistors – two, three, or four -wire measurements
Semiconductor temperature sensors – LM35, TMP35 or equivalent

The WLS-TEMP provides a 24-bit analog-to-digital (A/D) converter for each pair of differential analog input
channels. Each pair of differential inputs constitutes a channel pair. You can connect a different category of
sensor to each channel pair, but you can not mix categories among the channels that constitute a channel pair(although it is permissible to mix thermocouple types).
The WLS-TEMP provides two integrated cold junction compensation (CJC) sensors for thermocouple
measurements, and built-in current excitation sources for resistive sensor measurements.
An open thermocouple detection feature lets you detect a broken thermocouple. An onboard microprocessor
automatically linearizes the measurement data according to the sensor category.
The WLS-TEMP features eight independent temperature alarms. Each alarm controls an associated digital I/O
channel as an alarm output. The input to each alarm is one of the temperature input channels. The output of each
alarm is software-configurable as active high or low. You set up the temperature threshold conditions to activate
each alarm. When an alarm is activated, the associated DIO channel is driven to the output state.
All configurable options are software programmable. The WLS-TEMP is fully software-calibrated.
You can operate the WLS-TEMP as a standalone plug-and-play device which draws power through the USB
cable. You can also operate the WLS-TEMP as a remote device that communicates with the computer throughthe WLS-IFC USB-to-wireless interface device. An external power supply is shipped with the device to provide
power during remote operations.

Remote wireless operation
When operating as a remote device, the WLS-TEMP communicates with the computer through the WLS-IFC
device connected to the computer's USB port
Before you can operate the WLS-TEMP remotely, you must connect it to the computer's USB port andconfigure the network parameters required to establish a wireless link with the interface device. Only devices
with the same parameter settings can communicate with each other. All configurable options are programmablewith InstaCal.
LEDs on the WLS-TEMP indicate the status of communication over the wireless link. An LED bar graph shows
the fade margin of signals received by the WLS-TEMP.
For more information on setting up network parameters, refer to "Network parameters (remote operation)" onpage 10.
6

WLS-TEMP Specifications

WLS-TEMP block diagram
WLS-TEMP functions are illustrated in the block diagram shown here.

Figure 1. Functional block diagram

7

Chapter 2

Installing the WLS-TEMP
What comes with your shipment?
The following items are shipped with the WLS-TEMP:

Hardware

WLS-TEMP
AC-to-USB power adapter (2.5 watt supply for wireless operations) and USB cable (2 meter length)

Software

MCC DAQ Software CD

Documentation


Quick Start Guide
This booklet provides an overview of the MCC DAQ software you received with the device, and includes
information about installing the software. Please read this booklet completely before installing any softwareor hardware.
Setup Options
An overview of installation options is provided in the Wireless Setup document that ships with the device.

UnpackingAs with any electronic device, you should take care while handling to avoid damage from static
electricity. Before removing the WLS-TEMP from its packaging, ground yourself using a wrist strap or bysimply touching the computer chassis or other grounded object to eliminate any stored static charge.
If any components are missing or damaged, contact us immediately using one of the following methods:

Knowledgebase: kb.mccdaq.com
Phone: 508-946-5100 and follow the instructions for reaching Tech Support
Fax: 508-946-9500 to the attention of Tech Support
Email: techsupport@mccdaq.com

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

Installing the software
Refer to the Quick Start Guide for instructions on installing the software on the MCC DAQ CD. This booklet isavailable in PDF at www.mccdaq.com/PDFmanuals/DAQ-Software-Quick-Start.pdf.

Installing the hardware
Before you operate the WLS-TEMP as a local or remote device, first install it onto your system and configure itwith InstaCal.
Install the MCC DAQ software before you install the WLS-TEMP
The driver needed to run your board is installed with the MCC DAQ software. Therefore, you need to install the
MCC DAQ software before you install your board. Refer to the Quick Start Guide for instructions on installingthe software.

8

WLS-TEMP Specifications

Complete the following steps to connect the WLS-TEMP to your system:
1.

Turn your computer on, and connect the USB cable to a USB port on your computer or to an external USB
hub that is connected to your computer. The USB cable provides power and communication to the WLSTEMP.

Always connect an external hub to its power supply
If you are using a hybrid hub (one that can operate in either self-powered or bus-powered mode), always
connect it to its external power supply.
If you use a hub of this type without connecting to external power, communication errors may occur that could
result in corrupt configuration information on your wireless device. You can restore the factory default
configuration settings with InstaCal.
When you connect the WLS-TEMP for the first time, a notification message opens as the WLS-TEMP is
detected. After your system detects new hardware, the Found New Hardware Wizard opens and prompts
you to respond to the question "Can Windows connect to Windows Update to search for software?"2.

Click on the No, not this time option, and then click on the Next button.
The next dialog prompts you for the location of the software required to run the new hardware.

3.

Keep the default selection "Install the software automatically" and then click on the Next button.
The wizard locates and installs the software on your computer for the WLS-TEMP. A dialog appears when
the wizard completes the installation.

4.

Click on the Finish button to exit the Found New Hardware Wizard.

A dialog box opens when the hardware is installed and ready to use. The Command LED will blink and thenremain on to indicate that communication is established between the WLS-TEMP and your computer. The
Wireless Power LED turns on to indicate that the internal RF module is receiving power.

If the Command LED turns off
If the Command LED is on but then turns off, the computer has lost communication with the WLS-TEMP. If
the WLS-TEMP is connected to the computer USB port, disconnect the USB cable from the computer and thenreconnect it. This should restore communication, and the LED should turn back on.
If the Command LED turns off when you are operating the WLS-TEMP remotely through the wirelessinterface, disconnect the USB cable from the USB power adapter, and then reconnect it. This should restore
communication, and the Command LED should turn back on.

Configuring the hardware
Before using the WLS-TEMP, configure the temperature sensors and network parameters for remote wirelesscommunication. All hardware configuration options on the WLS-TEMP are programmable with InstaCal.
Configuration options are stored on the WLS-TEMP in non-volatile memory in EEPROM, and are loaded on
power up.

Temperature sensors
Use InstaCal to set the sensor type for each channel pair. The configurable options dynamically update
according to the selected sensor category. You can modify sensor settings when you operate the WLS-TEMP
remotely.
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WLS-TEMP Specifications

You can configure sensor settings when the WLS-TEMP is connected locally to the computer through the USB
port, or when the device is operated remotely through the wireless interface.
The factory-default sensor configuration is Disabled. The Disabled mode disconnects the analog inputs from theterminal blocks and internally grounds all of the A/D inputs. This mode also disables each of the current
excitation sources.

Network parameters (remote operation)
The following network parameter options are programmable with InstaCal.







Identifier: Text that identifies the device (optional).
PAN (hex): The personal area network (PAN) ID assigned to the device.

The PAN value is a number used to identify the interface device with which you want to communicate. The
WLS-TEMP can only communicate with a device whose PAN is set to the same value.
Most users do not need to change the default value assigned to the device. However, you may want toassign a different PAN ID in the following situations:o You have multiple WLS Series devices, and do not want to allow communication between all of them.
Set the PAN ID to the same value on each device that you want to communicate.
o If other WLS Series devices are operating in the vicinity, you can avoid accidental changes to yourdevice settings by changing the default PAN value.
CH: The radio frequency (RF) channel number assigned to the device.
The channel number is used to transmit and receive data over the wireless link. You may want to change
the channel number in InstaCal when another WLS Series device is already transmitting on that channel, or
when noise is present on the channel.
The table below lists each available channel and its corresponding transmission frequency:
RF
ChannelTransmission
Frequency (GHz)RF
ChannelTransmission
Frequency (GHz)

12
13
14
15
16
17

2.410
2.415
2.420
2.425
2.430
2.435

18
19
20
21
22
23

2.440
2.445
2.450
2.455
2.460
2.465

AES Key: Value used to encrypt data (optional).

AES encryption is disabled by default. Unless you suspect that there are other users of WLS Series devices
in the area, there should be no need to enable encryption. However, if you suspect that there are other WLS
Series devices in the area, and you need to secure the devices from being accessed by other users, enable
AES encryption.
Enabling encryption does NOT secure the device from access through a local USB connection. A remotedevice configured for encryption can be connected locally through the USB port to access other remote
WLS Series devices with the same settings; you may need to physically secure the remote devices toprevent tampering of the of device's network.
Set the PAN ID, RF channel, and AES key to the same value for each device that you want tocommunicate
Only devices with matching parameter settings for PAN, CH, and AES Key (if set) can communicate with eachother.
For information on setting up the network parameters for your WLS-TEMP, refer to the "WLS Series" sectionof the "Temperature Input Boards" chapter in the Universal Library User's Guide.
After configuring the network parameters, disconnect the WLS-TEMP from the computer, and move the device
to its remote location. The WLS-TEMP can be located up to 150 feet (50 meters) indoors, or up to ½ mile
(750 m) outdoors from the interface device.

10

WLS-TEMP Specifications

Restoring factory default settings
You can restore the factory default configuration settings with InstaCal.

Connecting the external power supply for remote operation
Connect the USB cable to the AC-to-USB power adapter when you are operating the WLS-TEMP remotely
through the wireless interface. The Command and Wireless Power LEDs turn on approximately five seconds
after you connect the AC power adapter.
Caution! To satisfy FCC RF exposure requirements for mobile transmitting devices, maintain a separation
distance of 20 cm (0.66 feet) or more between the antenna of this device and personnel during
device operation. To ensure compliance, operation at closer than this distance is notrecommended. The antenna used for this transmitter must not be co-located in conjunction withany other antenna or transmitter.

Calibrating the WLS-TEMP
You can fully calibrate the WLS-TEMP using InstaCal. Allow a 30-minute warm up before calibrating.
InstaCal prompts you to run its calibration utility if you change the sensor category. If you don't change thesensor category the normal calibration interval is once per year.
You can calibrate the WLS-TEMP when it is connected locally to the computer through the USB port, or when
it is operated remotely through the wireless interface.

Warm up time
Allow the WLS-TEMP to warm up for 30 minutes before taking measurements. This warm up time minimizes
thermal drift and achieves the specified rated accuracy of measurements.
For RTD or thermistor measurements, this warm-up time is also required to stabilize the internal current
reference.

11

Chapter 3

Sensor Connections
The WLS-TEMP supports the following temperature sensor types:Thermocouple – types J, K, R, S, T, N, E, and B
Resistance temperature detectors (RTDs) – two-, three-, or four-wire measurement modes of 100 Ω
platinum RTDs.
Thermistors – two-, three-, or four-wire measurement modes.
Semiconductor temperature sensors – LM35, TMP35 or equivalent

The type of sensor you select depends on your application needs. Review the temperature ranges and accuraciesof each sensor type to determine which is best suited for your application.

Screw terminal pinout
The WLS-TEMP has four banks of screw terminals. There are 26 connections on each side. Between each bankof screw terminals are two integrated CJC sensors used for thermocouple measurements. Signals are identified
in Figure 2.

Figure 2. Screw terminal pinout

Use 16 AWG to 30 AWG wire for your signal connections.
Tighten screw terminal connections
When making connections to the screw terminals, be sure to tighten the screw until tight. Simply touching the
top of the screw terminal is not sufficient to make a proper connection.

Sensor input
You can connect up to eight temperature sensors to the differential sensor inputs ( C0H/C0L to C7H/C7L).
Supported sensor categories include thermocouples, RTDs, thermistors, or semiconductor sensors.
Do not mix sensor categories within channel pairs. You can mix thermocouple types (J, K, R, S, T, N, E, and B)
within channel pairs, however.

12

WLS-TEMP Specifications

Do not connect two different sensor categories to the same channel pair
The WLS-TEMP provides a 24-bit A/D converter for each channel pair. Each channel pair can monitor one
sensor category. To monitor a sensor from a different category, connect the sensor to a different channel pair
(input terminals).

Current excitation output
The WLS-TEMP has four dedicated pairs of current excitation output terminals (± I1 to ±I4). These terminals
have a built-in precision current source to provide excitation for the resistive sensors used for RTD andthermistor measurements.
Each current excitation terminal is dedicated to one pair of sensor input channels:I1+ is the current excitation source for channel 0 and channel 1
I2+ is the current excitation source for channel 2 and channel 3
I3+ is the current excitation source for channel 4 and channel 5
I4+ is the current excitation source for channel 6 and channel 7

Four-wire, two sensor common
Terminals 4W01, 4W23, 4W45, and 4W67 are used as the common connection for four-wire configurations with
two RTD or thermistor sensors.

Two sensor common
Terminals IC01, IC23, IC45, and IC67 are used as the common connection for two-wire configurations with two
RTD or thermistor sensors.

CJC sensors
The WLS-TEMP has two built-in high-resolution temperature sensors. One sensor is located on the right side,
and one sensor is located at the left side.

Digital I/O
You can connect up to eight digital I/O lines to the screw terminals labeled DIO0 to DIO7. Each terminal issoftware-configurable for input or output.

Power output
The two +5V output terminals are isolated (500 VDC) from the USB +5V.
Caution! The +5V terminal is an output. Do not connect an external power supply to this terminal or you
may damage the WLS-TEMP and possibly the computer.

GroundThe six ground terminals (GND) provide a common ground for the input channels and DIO bits, and are isolated(500 VDC) from the USB GND.

Thermocouple connections
A thermocouple consists of two dissimilar metals that are joined together at one end. When the junction of themetals is heated or cooled, a voltage is produced that correlates to temperature.
The WLS-TEMP makes fully-differential thermocouple measurements without the need of ground-referencing
resistors. A 32-bit floating point value in either a voltage or temperature format is returned by software. An
open thermocouple detection feature is available for each analog input which automatically detects an open or
broken thermocouple.
Use InstaCal to select the thermocouple type (J, K, R, S, T, N, E, and B) and one or more sensor input channels
to connect the thermocouple.
13

WLS-TEMP Specifications

Wiring configuration
Connect the thermocouple to the WLS-TEMP using a differential configuration, as shown in Figure 3.

Figure 3. Typical thermocouple connection

Connect thermocouples to the WLS-TEMP so that they float with respect to ground. The GND pins are isolated
from earth ground, so you can connect thermocouple sensors to voltages referenced to earth ground as long as
you maintain the isolation between the GND pins and earth ground.
When you attach thermocouples to conductive surfaces, the voltage differential between multiple
thermocouples must remain within ±1.4 V. For best results, we recommend the use of insulated or ungrounded
thermocouples when possible.
Maximum input voltage between analog input and ground
The absolute maximum input voltage between an analog input and the isolated GND pins is ±25 VDC when thedevice is powered on, and ±40 VDC when the device is powered off.
If you need to increase the length of your thermocouple, use the same type of thermocouple wires to minimize
the error introduced by thermal EMFs.

RTD and thermistor connections
A resistance temperature detector (RTD) measures temperature by correlating the resistance of the RTD
element with temperature. A thermistor is a thermally-sensitive resistor that is similar to an RTD in that its
resistance changes with temperature. Thermistors show a large change in resistance that is proportional to asmall change in temperature. The main difference between RTD and thermistor measurements is the method
used to linearize the sensor data.
RTDs and thermistors are resistive devices that need an excitation current to produce a voltage drop that can bemeasured differentially across the sensor. The WLS-TEMP features four built-in current excitation sources (±I1
to ±I4) for measuring resistive type sensors. Each current excitation source is dedicated to one channel pair.
The WLS-TEMP makes two, three, and four-wire measurements of RTDs (100 Ω platinum type) andthermistors.
Use InstaCal to select the sensor type and the wiring configuration. Once the resistance value is calculated, thevalue is linearized in order to convert it to a temperature value. A 32-bit floating point value in either
temperature or resistance is returned by software.


In RTD mode, the WLS-TEMP cannot measure resistance values greater than 660 Ω. This 660 Ω resistancelimit includes the total resistance across the current excitation (±Ix) pins, which is the sum of the RTD
resistance and the lead resistances.
In thermistor mode, the WLS-TEMP cannot measure resistance values greater than 180 kΩ. This 180 kΩ
resistance limit includes the total resistance across the current excitation (±Ix) pins, which is the sum of thethermistor resistance and the lead resistance.

14

WLS-TEMP Specifications

Two-wire configuration
The easiest way to connect an RTD sensor or thermistor to the WLS-TEMP is with a two-wire configuration,
since it requires the fewest connections to the sensor. With this method, the two wires that provide the RTD
sensor with its excitation current also measure the voltage across the sensor.
Since RTDs exhibit a low nominal resistance, the lead wire resistance can affect measurement accuracy. For
example, connecting lead wires that have a resistance of 1 Ω (0.5 Ω each lead) to a 100 Ω platinum RTD results
in a 1% measurement error.
With a two-wire configuration, you can connect either one sensor per channel pair, or two sensors per channel
pair.
Two-wire, single-sensor
A two-wire, single-sensor measurement configuration is shown in Figure 4.

Figure 4. Two-wire, single RTD or thermistor sensor measurement configuration

When you select a two-wire, single-sensor configuration with InstaCal, connections to C#H and C#L are madeinternally.
Two-wire, two sensor
A two-wire, two-sensor measurement configuration is shown in Figure 5.

Figure 5. Two-wire, two RTD or thermistor sensors measurement configuration

When you select a two-wire, two-sensor configuration with InstaCal, connections to C#H (first sensor) andC#H/C#L (second sensor) are made internally.
When configured for two-wire mode, connect both sensors to obtain proper measurements.

15

WLS-TEMP Specifications

Three-wire configuration
A three-wire configuration compensates for lead-wire resistance by using a single-voltage sense connection.
With a three-wire configuration, you can connect only one sensor per channel pair. A three-wire measurement
configuration is shown in Figure 6.

Figure 6. Three-wire RTD or thermistor sensor measurement configuration

When you select a three-wire sensor configuration with InstaCal, the WLS-TEMP measures the lead resistanceon the first channel (C#H/C#L) and measures the sensor itself using the second channel (C#H/C#L). Thisconfiguration compensates for any lead-wire resistance and temperature change in lead-wire resistance.
Connections to C#H for the first channel and C#H/C#L of the second channel are made internally.
For accurate three wire compensation, the individual lead resistances connected to the ±I# pins must be of equal
resistance value.

Four-wire configuration
With a four-wire configuration, connect two sets of sense/excitation wires at each end of the RTD or thermistor
sensor. This configuration completely compensates for any lead-wire resistance and temperature change in leadwire resistance.
Connect your sensor with a four-wire configuration when your application requires very high accuracy
measurements.
You can configure the WLS-TEMP with either a single sensor per channel or two sensors per channel pair.
Four-wire, single-sensor
A four-wire measurement configuration is shown in Figure 7. The diagram on the left shows the sensor
connected to the first channel in the channel pair. The diagram on the right shows the sensor connected to thesecond channel in the channel pair. The # indicates the channel number. Do not make connections to pinmarked "NC".

Figure 7. Four-wire, single RTD or thermistor sensor measurement configuration

16

WLS-TEMP Specifications

Four-wire, two-sensor
A four-wire, two-sensor measurement configuration is shown in Figure 8.

Figure 8. Four-wire, two RTD or thermistor sensors measurement configuration

When configured for four-wire, two sensor mode, both sensors must be connected to obtain proper
measurements.

Semiconductor sensor measurements
Semiconductor sensors are suitable over a range of approximately -40 C to 125 C, where an accuracy of±2 C is adequate. The temperature measurement range of a semiconductor sensor is small when compared tothermocouples and RTDs. However, semiconductor sensors are accurate, inexpensive, and easily interface withother electronics for display and control.
The WLS-TEMP makes high-resolution measurements of semiconductor sensors and returns a 32-bit floating
point value in either a voltage or temperature.
Use InstaCal to select the sensor type (LM35, TMP35 or equivalent), and the sensor input channel that connects
to the sensor.

Wiring configuration
You can connect a semiconductor sensor to the WLS-TEMP using a single-ended configuration, as shown in
Figure 9. The WLS-TEMP also provides +5V and GND pins for powering the sensor.

Figure 9. Semiconductor sensor measurement configuration

Digital I/O connections
You can connect up to eight digital I/O lines to the screw terminals labeled DIO0 to DIO7. You can configure
each digital bit for either input or output. All digital I/O lines are pulled up to +5V with a 47 K ohm resistor(default). You can request the factory to configure the resistor for pull-down to ground if desired.
When you configure the digital bits for input, you can use the WLS-TEMP digital I/O terminals to detect thestate of any TTL-level input. Refer to the schematic shown in Figure 10. If you set the switch to the +5V input,
DIO0 reads TRUE (1). If you move the switch to GND, DIO0 reads FALSE (0).

17WLS-TEMP Specifications

Figure 10. Schematic showing switch detection by digital channel DIO0

Caution! All ground pins on the WLS-TEMP (pins 9, 19, 28, 38) are common and are isolated from earth
ground. If a connection is made to earth ground when using digital I/O and conductive
thermocouples, the thermocouples are no longer isolated. In this case, thermocouples must not be
connected to any conductive surfaces that may be referenced to earth ground.
For general information regarding digital signal connections and digital I/O techniques, refer to the Guide to
Signal Connections (available on our web site at www.mccdaq.com/signals/signals.pdf).

Configuring the DIO channels to generate alarms
The WLS-TEMP features eight independent temperature alarms. All alarm options are software configurable.
Remote alarm configuration is supported.
When a digital bit is configured as an alarm, that bit is configured as an output on the next power cycle andassumes the state defined by the alarm configuration.
Each alarm controls an associated digital I/O channel as an alarm output. The input to each alarm is one of thetemperature input channels. You set up the temperature conditions to activate an alarm, and also the output stateof the channel (active high or low) when activated. When an alarm is activated, its associated DIO channel isdriven to the output state specified.
The alarm configurations are stored in non-volatile memory and are loaded on power up. The temperature
alarms function in wireless operations and while attached to the USB port on a computer.
You can configure alarm settings when you connect the WLS-TEMP locally to the computer through the USB
port, or when operating it remotely through the wireless interface.

18

Chapter 4

Functional Details
Thermocouple measurements
A thermocouple consists of two dissimilar metals that are joined together at one end. When the junction of themetals is heated or cooled, a voltage is produced that correlates to temperature.
The WLS-TEMP hardware level-shifts the thermocouple’s output voltage into the A/D’s common mode input
range by applying +2.5 V to the thermocouple’s low side at the C#L input. Always connect thermocouple
sensors to the WLS-TEMP in a floating fashion. Do not attempt to connect the thermocouple low side C#L to
GND or to a ground referencing resistor.

Cold junction compensation (CJC)
When you connect the thermocouple sensor leads to the sensor input channel, the dissimilar metals at the WLSTEMP terminal blocks produce an additional thermocouple junction. This junction creates a small voltage error
term which must be removed from the overall sensor measurement using a cold junction compensation
technique. The measured voltage includes both the thermocouple voltage and the cold junction voltage. To
compensate for the additional cold junction voltage, the WLS-TEMP subtracts the cold junction voltage fromthe thermocouple voltage.
The WLS-TEMP has two high-resolution temperature sensors that are integrated into the design of the WLSTEMP. One sensor is located on the right side of the package, and one sensor is located at the left side. The CJC
sensors measure the average temperature at the terminal blocks so that the cold junction voltage can becalculated. A software algorithm automatically corrects for the additional thermocouples created at the terminal
blocks by subtracting the calculated cold junction voltage from the analog input's thermocouple voltage
measurement.
Increasing the thermocouple length
If you need to increase the length of your thermocouple, use the same type of thermocouple wires to minimize
the error introduced by thermal EMFs.

Data linearization
After the CJC correction is performed on the measurement data, an onboard microcontroller automaticallylinearizes the thermocouple measurement data using National Institute of Standards and Technology (NIST)
linearization coefficients for the selected thermocouple type.
The measurement data is then output as a 32-bit floating point value in the configured format (voltage ortemperature).

Open-thermocouple detection (OTD)
Open-thermocouple detection (OTD) is automatically enabled for each analog input channel when a channel
pair is configured for thermocouple sensor. The maximum open detection time is 3 seconds.
With OTD, any open-circuit or short-circuit condition at the thermocouple sensor is detected by the software.
An open channel is detected by driving the input voltage to a negative value outside the range of any
thermocouple output. The software recognizes this as an invalid reading and flags the appropriate channel. The
software continues to sample all channels when OTD is detected.
Input leakage current
With open-thermocouple detection enabled, a maximum of 105 nA of input leakage current is injected into thethermocouple. This current can cause an error voltage to develop across the lead resistance of the thermocouple
that is indistinguishable from the thermocouple voltage you are measuring.
You can estimate this error voltage with the following formula:

19

WLS-TEMP Specifications

error voltage = resistance of the thermocouple x 105 nA

To reduce the error, reduce the length of the thermocouple to lower its resistance, or lower the AWG of the wireby using a wire with a larger diameter. With OTD disabled, a maximum of 30 nA of input leakage current is
injected into the thermocouple.

RTD and thermistor measurements
RTDs and thermistors are resistive devices that require an excitation current to produce a voltage drop that canbe measured differentially across the sensor. The WLS-TEMP measures the sensor resistance by forcing aknown excitation current through the sensor and then measuring (differentially) the voltage across the sensor todetermine its resistance.
After the voltage measurement is made, the resistance of the RTD is calculated using Ohms law – the sensor
resistance is calculated by dividing the measured voltage by the current excitation level (± Ix) source. The valueof the ±Ix source is stored in local memory.
Once the resistance value is calculated, the value is linearized in order to convert it to a temperature value. The
measurement is returned by software as a 32-bit floating point value in a voltage, resistance or temperatureformat.

Data linearization
An onboard microcontroller automatically performs linearization on RTD and thermistor measurements.


RTD measurements are linearized using a Callendar-Van Dusen coefficients algorithm (you select DIN,
SAMA, or ITS-90).
Thermistor measurements are linearized using a Steinhart-Hart linearization algorithm (you supply thecoefficients from the sensor manufacturer's data sheet).

AC power supply
The external power supply is an AC-to-USB 2.5 W supply that is used to power the WLS-TEMP during remotewireless operations (MCC p/n USB Power Adapter.)External components
The WLS-TEMP has the following external components, as shown in Figure 11.
Screw terminals
USB connector
Status LEDs (Command, Wireless Power, Transmit, Receive, Received Signal Strength indicators)
LED Test button

20

WLS-TEMP Specifications

1
2
3
4
5

Screw terminal pins 1 to 26
Screw terminal pins 27 to 52
Command LED
LED Test button
Received Signal Strength (RSS) LEDs

6
7
8
9

Receive LED
Transmit LED
Wireless Power LED
USB connector

Figure 11. WLS-TEMP component locations

Screw terminals
The device's four banks of screw terminals are for connecting temperature sensors and digital I/O lines. Theseterminals also provide ground and power output connections. Refer to "Screw terminal pinout" on page 12 forscrew terminal descriptions.
Caution! The two +5V terminals (pin 21 and pin 47) are isolated (500 VDC) from the USB +5V. Each +5V
terminal is an output. Do not connect to an external power supply or you may damage the WLSTEMP and possibly the computer.

USB connector
The USB connector provides +5V power and communication. External power is required to operate the WLSTEMP remotely through the wireless interface.
For local operation, connect to the USB port or hub on your computer. For remote wireless operation, connect
to the external AC adapter shipped with the device.

Status LEDs
The LEDs indicate the communication status of USB and wireless operations. In addition, three LEDs indicate
the signal strength of data received over the wireless link. Refer to the table below for the function of each LED.
LED functions
LED

Function

Command

Steady green – the WLS-TEMP is connected to a computer or AC adapter
Blinking green – the WLS-TEMP is receiving a command over the USB or wireless link.
The WLS-TEMP internal RF device is receiving power (USB or AC adapter).
Data is being transmitted over an active wireless link.
Data is being received over an active wireless link.

Wireless Power (green)
Transmit (yellow)
Receive (red)21

WLS-TEMP Specifications

LED

Function

Received Signal Strength(RSS) Indicator LEDs

3 green LED bar graph. The LEDs will turn on when receiving a wireless message andstay on for approximately 1 second after the end of the message. They indicate theamount of fade margin present in an active wireless link. Fade margin is defined as thedifference between the incoming signal strength and the device’s receiver sensitivity.
 Three LEDs on: Very strong signal (> 30 dB fade margin)
 Two LEDs on: Strong signal (> 20 dB fade margin) One LED on: Moderate signal (> 10 dB fade margin)
 No LEDs on: Weak signal (< 10 dB fade margin)

LED Test button
The LED test button tests the functionality of the LEDs. When pressed, each LED lights in sequence (first theCommand LED then left to right from the Wireless Power LED to the RSS indicator LEDs).

22

Chapter 5

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. Generic analog input specifications
Parameter

Condition

Specification

A/D converters

Four dual 24-bit, Sigma-Delta type

Number of channels

8 differential

Input isolation

500 VDC minimum between field wiring andUSB interface
Software programmable to match sensor type±0.080 V
0 to 0.5 V
0 to 2 V
0 to 2.5 V±25 V power on±40 V power off
5 GΩ, min

Channel configuration
Differential input voltage
range

Absolute maximum input
voltage

Thermocouple
RTD
Thermistor
Semiconductor sensor±C0x through ±C7x relative to GND

Input impedance
Input leakage current
Normal mode rejection ratio
Common mode rejection
ratio
Resolution

Open thermocouple detect disabledOpen thermocouple detect enabled
fIN =60 Hz
fIN =50 Hz/60 Hz

30 nA max
105 nA max
90 dB min
100 dB min
24 bits

No missing codes
Input coupling

24 bits
DC

Warm-up time

30 minutes min

Open thermocouple detect

Automatically enabled when the channel pair isconfigured for thermocouple sensor.
The maximum open detection time is 3 seconds.
±0.25 °C typ,±0.5 °C max–1.0 °C to +0.5 °C max

CJC sensor accuracy

15 °C to 35 °C
0 °C to 70 °C

23

WLS-TEMP Specifications

Channel configurations
Table 2. Channel configuration specifications
Sensor Category

Condition

Max number of
sensors (all channels
configured alike)

Thermocouple
Semiconductor sensor

J, K, S, R, B, E, T, or N

8 differential channels
8 differential channels

RTD and thermistor

2-wire input configuration with a single sensor per channelpair
2-wire input configuration with two sensors per channel pair
3-wire configuration with a single sensor per channel pair
4-wire input configuration with a single sensor per channelpair
4-wire input configuration with two sensors per channel pair

4 differential channels

Disabled

8 differential channels
4 differential channels
4 differential channels
8 differential channels

Note 1: Internally, the device has four dual-channel, fully differential A/Ds providing a total of eight

differential channels. The analog input channels are therefore configured in four channel pairs with
CH0/CH1 sensor inputs, CH2/CH3 sensor inputs, CH4/CH5 sensor inputs, and CH6/CH7 sensor
inputs paired together. This "channel-pairing" requires the analog input channel pairs be configured tomonitor the same category of temperature sensor. Mixing different sensor types of the same category(such as a type J thermocouple on channel 0 and a type T thermocouple on channel 1) is valid.
Note 2: Channel configuration information is stored in the EEPROM of the isolated microcontroller by thefirmware whenever any item is modified. Modification is performed by commands issued over USB or
wireless from an external application, and the configuration is made non-volatile through the use of the
EEPROM.
Note 3: The factory default configuration is Disabled. The Disabled mode will disconnect the analog inputs
from the terminal blocks and internally ground all of the A/D inputs. This mode also disables each of
the current excitation sources.

Compatible sensors
Table 3. Compatible sensor type specifications
Parameter

Condition

Thermocouple

J: –210 °C to 1200 °C
K: –270 °C to 1372 °C
R: –50 °C to 1768 °C
S: –50 °C to 1768 °C
T: –270 °C to 400 °C
N: –270 °C to 1300 °C
E: –270 °C to 1000 °C
B: 0 °C to 1820 °C
100 Ω PT (DIN 43760: 0.00385 ohms/ohm/°C)
100 ΩPT (SAMA: 0.003911 ohms/ohm/°C)
100 Ω PT (ITS-90/IEC751:0.0038505 ohms/ohm/°C)Standard 2,252 Ω through 30,000 Ω
LM35, TMP35 or equivalent

RTD

Thermistor
Semiconductor / IC24

WLS-TEMP Specifications

Accuracy
Thermocouple measurement accuracy
Table 4. Thermocouple accuracy specifications, including CJC measurement error
Sensor TypeMaximum error (°C)

Typical error (°C)

Temperature range (°C)

J

±1.499±0.643±1.761±0.691±2.491±1.841±2.653±1.070±1.779±0.912±1.471±0.639±1.717±0.713±1.969±0.769±0.507±0.312±0.538±0.345±0.648±0.399±0.650±0.358±0.581±0.369±0.462±0.245±0.514±0.256±0.502±0.272–210 to 0
0 to 1200–210 to 0
0 to 1372–50 to 250
250 to 1768.1–50 to 250
250 to 1768.1
250 to 700
700 to 1820
–200 to 0
0 to 1000–200 to 0
0 to 600–200 to 0
0 to 1300

K
S
R
B
E
T
N

Note 4: Thermocouple measurement accuracy specifications include linearization, cold-junction compensationand system noise. These specs are for one year, or 3000 operating hours, whichever comes first, andfor operation of the device between 15 °C and 35 °C. For measurements outside this range, add ±0.5
degree to the maximum error shown. There are CJC sensors on each side of the module. The accuracy
listed above assumes the screw terminals are at the same temperature as the CJC sensor. Errors shown
do not include inherent thermocouple error. Please contact your thermocouple supplier for details on
the actual thermocouple error.
Note 5: Thermocouples must be connected to the device such that they are floating with respect to GND (pins9, 19, 28, 38). The device GND pins are isolated from earth ground, so connecting thermocouple
sensors to voltages referenced to earth ground is permissible as long as the isolation between the GND
pins and earth ground is maintained.
Note 6: When thermocouples are attached to conductive surfaces, the voltage differential between multiple
thermocouples must remain within ±1.4 V. For best results we recommend the use of insulated or
ungrounded thermocouples when possible.

Semiconductor sensor measurement accuracy
Table 5. Semiconductor sensor accuracy specifications
Sensor Type

Temperature Range (°C)

Maximum Accuracy Error

LM35, TMP35 orequivalent–40 to 150±0.50Note 7: Error shown does not include errors of the sensor itself. These specs are for one year while operationof the device is between 15 °C and 35 °C. Please contact your sensor supplier for details on the actual
sensor error limitations.

25

WLS-TEMP Specifications

RTD measurement accuracy
Table 6. RTD measurement accuracy specifications
RTD

SensorTemperature (°C)

Maximum Accuracy Error (°C)
Ix+ = 210 µA

Typical Accuracy Error (°C)
Ix+ = 210 µA

PT100, DIN, US or
ITS-90–200 to –150
–150 to –100
–100 to 0
0 to 100
100 to 300
300 to 600

±2.85
±1.24
±0.58
±0.38
±0.39
±0.40

±2.59
±0.97
±0.31
±0.11
±0.12
±0.12

Note 8: Error shown does not include errors of the sensor itself. The sensor linearization is performed using a

Callendar-Van Dusen linearization algorithm. These specs are for one year while operation of thedevice is between 15 °C and 35 °C. The specification does not include lead resistance errors for 2-wire
RTD connections. Please contact your sensor supplier for details on the actual sensor error limitations.
Note 9: Resistance values greater than 660 Ω cannot be measured by the device in the RTD mode. The 660 Ω
resistance limit includes the total resistance across the current excitation (±Ix) pins, which is the sum of
the RTD resistance and the lead resistances.
Note 10:
For accurate three wire compensation, the individual lead resistances connected to the ±Ix pins
must be of equal value.

Thermistor measurement accuracy
Table 7. Thermistor measurement accuracy specifications
Thermistor

Temperature range (°C)

Maximum accuracy error (°C)
Ix+ = 10 µA

2252 Ω

–40 to120±0.05

3000 Ω
5000 Ω

–40 to120–35 to120

±0.05
±0.05

10000 Ω30000 Ω–25 to120–10 to120

±0.05
±0.05

Note 11:

Error shown does not include errors of the sensor itself. The sensor linearization is performed
using a Steinhart-Hart linearization algorithm. These specs are for one year while operation of thedevice is between 15 °C and 35 °C. The specification does not include lead resistance errors for 2-wirethermistor connections. Please contact your sensor supplier for details on the actual sensor error
limitations. Total thermistor resistance on any given channel pair must not exceed 180 k Ω. Typicalresistance values at various temperatures for supported thermistors are shown in Table 8.
Table 8. Typical thermistor resistance specifications

Temp
(°C)

2252 Ω
thermistor

3000 Ω
thermistor

5 kΩ
thermistor

10 kΩ
thermistor

30 kΩ
thermistor

–40
–35

76 kΩ
55 kΩ

101 kΩ
73 kΩ

168 kΩ
121 kΩ

240 kΩ (Note 12)
179 kΩ

885 kΩ (Note 12)649 kΩ (Note 12)

–30
–25

40 kΩ
29 kΩ

53 kΩ
39 kΩ

88 kΩ
65 kΩ

135 kΩ
103 kΩ

481 kΩ (Note 12)
360 kΩ (Note 12)

–20
–15

22 kΩ
16 kΩ

29 kΩ
22 kΩ

49 kΩ
36 kΩ

79 kΩ
61 kΩ

271 kΩ (Note 12)
206 kΩ (Note 12)

–10
–5

12 kΩ
9.5 kΩ

17 kΩ
13 kΩ

28 kΩ
21 kΩ

48 kΩ
37 kΩ

158 kΩ
122 kΩ

0

7.4 kΩ

9.8 kΩ

16 kΩ

29 kΩ

95 kΩ

26

WLS-TEMP Specifications

Resistance values greater than 180 kΩ cannot be measured by the device in the thermistor mode.
The 180 kΩ resistance limit includes the total resistance across the current excitation (±Ix) pins, whichis the sum of the thermistor resistance and the lead resistances.
Note 13:
For accurate three wire compensation, the individual lead resistances connected to the ±Ix pins
must be of equal value.
Note 12:

Throughput rate to PC (USB or wireless)
Table 9. Throughput rate specifications
Number of input channels

Maximum throughput

1
2
3
4
5
6
7
8

2 Samples/second
2 S/s on each channel, 4 S/s total
2 S/s on each channel, 6 S/s total
2 S/s on each channel, 8 S/s total
2 S/s on each channel, 10 S/s total
2 S/s on each channel, 12 S/s total
2 S/s on each channel, 14 S/s total
2 S/s on each channel, 16 S/s total

Note 14:

The analog inputs are configured to run continuously. Each channel is sampled twice per second.
The maximum latency between when a sample is acquired and the temperature data is provided by thedevice is approximately 0.5 seconds

Digital input/output
Table 10. Digital input/output specifications
Parameter

Specification

Digital type
Number of I/O
Configuration

CMOS
8 (DIO0 through DIO7)
Independently configured for input or output.
Power on reset is input mode unless bit is configured for alarm.
All pins pulled up to +5 V via 47 kΩ resistors (default). Pull down to ground (GND) alsoavailable.
 Digital input: 50 port reads or single bit reads per second, typ Digital output: 100 port writes or single bit writes per second, typ
2.0 V min, 5.5 V absolute max
0.8 V max, –0.5 V absolute min
0.7 V max

Pull up/pull-down
configuration
Digital I/O transfer rate
(software paced)
Input high voltage
Input low voltage
Output low voltage(IOL = 2.5 mA)
Output high voltage(IOH = –2.5 mA)
Note 15:

3.8 V minAll ground pins are common and are isolated from earth ground. If a connection is made to earth
ground when using digital I/O and conductive thermocouples, the thermocouples are no longer
isolated. In this case, thermocouples must not be connected to any conductive surfaces that may bereferenced to earth ground.

27

WLS-TEMP Specifications

Temperature alarms
Table 11. Temperature alarm specifications
Parameter

Specification

Number of alarms
Alarm functionality

8 (one per digital I/O line)
Each alarm controls its associated digital I/O line as an alarm output. The input to each
alarm may be any of the analog temperature input channels. When an alarm is enabled, its
associated I/O line is set to output (after the device is reset) and driven to the appropriate
state determined by the alarm options and input temperature. The alarm configurations are
stored in non-volatile memory and are loaded at power on. Alarms will function both inwireless mode and while attached to USB.
 Alarm when input temperature > T1
 Alarm when input temperature > T1, reset alarm when input temperature goes below T2
 Alarm when input temperature < T1
 Alarm when input temperature < T1, reset alarm when input temperature goes above T2
 Alarm when input temperature is < T1 or > T2
Note: T1 and T2 may be independently set for each alarm.
 Disabled, digital I/O line may be used for normal operation
 Enabled, active high output (digital I/O line goes high when alarm conditions met) Enabled, active low output (digital I/O line goes low when alarm conditions met)
1 second

Alarm input modes

Alarm output modes

Alarm update rate

MemoryTable 12. Memory specifications
Parameter

Specification

EEPROM

1,024 bytes isolated micro reserved for sensor configuration
256 bytes USB micro for external application use

Microcontroller
Table 13. Microcontroller specifications
Parameter

Specification

Type

Three high performance 8-bit RISC microcontrollers

Wireless communications
Table 14. Wireless Communications specifications
Parameter

Specification

Communication standard
Range

IEEE 802.15.4, ISM 2.4GHz frequency band, non-beacon, point-to-point
Indoor/urban: Up to 150' (50 m)
Outdoor RF line-of-sight: Up to 1/2 mile (750 m)
10 mW (10 dBm)
–100 dBm (1% packet error rate)
12 direct sequence channels available, channels 12 – 23 (2.410 – 2.465 GHz)
(software selectable)
16-bit PAN (personal area network) IDs per channel (software selectable)
64-bit device address
128-bit AES (software selectable)

Transmit power output
Receiver sensitivity
RF channels
Addressing
Encryption

28

WLS-TEMP Specifications

Contains FCC ID: OUR-XBEEPRO. The enclosed device complies with Part 15 of the FCC
Rules. Operation is subject to the following two conditions: (i.) this device may not cause harmfulinterference and (ii.) this device must accept any interference received, including interference that may
cause undesired operation.
Note 17:
Canada: Contains Model XBee Radio, IC: 4214A-XBEEPRO
Note 16:

Caution! To satisfy FCC RF exposure requirements for mobile transmitting devices, a separation distanceof 20 cm or more should be maintained between the antenna of this device and persons during
device operation. To ensure compliance, operations at closer than this distance is notrecommended. The antenna used for this transmitter must not be co-located in conjunction withany other antenna or transmitter.

USB +5V voltage
Table 15. USB +5V voltage specifications
Parameter

Specification

USB +5V (VBUS) input voltage range

4.75 V min to 5.25 V max

Power
Table 16. Power specifications
Parameter

Condition

Specification

Connected to USB
Supply current
User +5V output voltage range(terminal block pin 21 and 47)
User +5V output current(terminal block pin 21 and pin 47)
Isolation

Connected to a self-powered hub. (Note 18)

500 mA max
4.75 V min to
5.25 V max
10 mA max

Measurement system to PC

500 VDC min

Connected to a self-powered hub. (Note 18)

Wireless Communications operation
Supply current

500 mA max

AC Adapter Power Supply (used for remote wireless communications operation)
Standalone power supply

USB power adapter
2.5 Watt USB adapter withinterchangeable plugs(Includes plug for USA)
5 V ±5%
2.5 W
100 VAC to 240 VAC
50 Hz to 60 Hz
0.2 A

Output voltage
Output wattage
Input voltage
Input current
Note 18:

Self-Powered Hub refers to a USB hub with an external power supply. Self-powered hubs allow aconnected USB device to draw up to 500 mA. This device may not be used with bus-powered hubs dueto the power supply requirements.
Root Port Hubs reside in the PC USB Host Controller. The USB port(s) on your PC are root port hubs.
All externally powered root port hubs (desktop PC) provide up to 500 mA of current for a USB device.
Battery-powered root port hubs provide 100 mA or 500 mA, depending upon the manufacturer. A
laptop PC that is not connected to an external power adapter is an example of a battery-powered root
port hub.

29

WLS-TEMP Specifications

USB specifications
Table 17. USB specifications
Parameter

Specification

USB device type
Device compatibility

USB 2.0 (full-speed)
USB 1.1, USB 2.0
Bus powered, 500 mA consumption max

USB cable type

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

Current excitation outputs (Ix+)
Table 18. Current excitation output specifications
Parameter

Specification

Configuration

4 dedicated pairs:±I1: CH0/CH1±I2: CH2/CH3±I3: CH4/CH5±I4: CH6/CH7
Thermistor: 10 µA typ
RTD: 210 µA typ±5% typ
200 ppm/°C
2.1 ppm/V max
0.3 ppm/V typ
3.90 V max–0.03 V min

Current excitation output ranges
Tolerance
DriftLine regulation
Load regulation
Output compliance voltage (relative to
GND pins 9, 19, 28, 38)

The device has four current excitation outputs, with ±I1 dedicated to the CH0/CH1 analog inputs,±I2 dedicated to CH2/CH3, ±I3 dedicated to CH4/CH5, and ±I4 dedicated to CH6/CH7. The excitation
output currents should always be used in this dedicated configuration.
Note 20:
The current excitation outputs are automatically configured based on the sensor selected(thermistor or RTD).
Note 19:

Environmental
Table 19. Environmental specifications
Parameter

Specification

Operating temperature range
Storage temperature range
Humidity

0 °C to 70 °C–40 °C to 85 °C
0% to 90% non-condensing

Mechanical
Table 20. Mechanical specifications
Parameter

Specification

Dimensions (L × W × H)User connection length

128.52 x 88.39 × 35.56 mm (5.06 × 3.48 × 1.43 ft)
3 m (9.84 ft) max

30

WLS-TEMP Specifications

LED / button configuration
Table 21. LED configuration
Parameter

Specification

Command LED

Green LED – indicates a command was received by the device (either USB or
wireless)Three green LED bar graph.
LEDs turn on when receiving a wireless message and stay on for approximately
1 second after the end of the message. The LEDs indicate the amount of fademargin present in an active wireless link. Fade margin is defined as the difference
between the incoming signal strength and the receiver sensitivity of the device.
 3 LEDs on: Very strong signal (>30 dB fade margin) 2 LEDs on: Strong signal (>20 dB fade margin) 1 LED on: Moderate signal (>10 dB fade margin)
 0 LED on: Weak signal (<10 dB fade margin)
Green LED: indicates that the internal RF module is powered.
Yellow LED: indicates transmitting data over the wireless link.
Red LED: indicates receiving data over the wireless link.
Firmware-defined; this revision executes an LED test.

Received Signal Strength Indicator(RSSI) LEDs

Wireless Power LED
Transmit LED
Receive LED
Button31

WLS-TEMP Specifications

Screw terminal connector
Table 22. Screw terminal connector specifications
Connector type
Wire gauge range

Screw terminal
16 AWG to 30 AWG
Table 23. Screw terminal pinout

Pin
1
2
3
4
5
6
7
8
9
10

Signal Name
I1+
NC
C0H
C0L
4W01
IC01
C1H
C1L
GND
I1–

Pin Description
CH0/CH1 current excitation source
No connection
CH0 sensor input (+)
CH0 sensor input (–)
CH0/CH1 4-wire, 2 sensor common
CH0/CH1 2-sensor common
CH1 sensor input (+)
CH1 sensor input (–)
GroundCH0/CH1 current excitation return

Pin
27
28
29
30
31
32
33
34
35
36

CJC sensor
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26

I2+
NC
C2H
C2L
4W23
IC23
C3H
C3L
GND
I2–
+5V
GND
DIO0
DIO1
DIO2
DIO3

Signal Name Pin Description
I4–
CH6/CH7 current excitation return
GND
GroundC7L
CH7 sensor input (–)
C7H
CH7 sensor input (+)
IC67
CH6/CH7 2 sensor common
4W67
CH6/CH7 4-wire, 2 sensor common
C6L
CH6 sensor input (–)
C6H
CH6 sensor input (+)
NC
No connection
I4+
CH6/CH7 current excitation source
CJC sensor

CH2/CH3 current excitation source
No connection
CH2 sensor input (+)
CH2 sensor input (–)
CH2/CH3 4-wire, 2 sensor common
CH2/CH3 2 sensor common
CH3 sensor input (+)
CH3 sensor input (–)
GroundCH2/CH3 current excitation return+5V output
GroundDIO channel 0
DIO channel 1
DIO channel 2
DIO channel 3

32

37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52

I3–
GND
C5L
C5H
IC45
4W45
C4L
C4H
NC
I3+
+5V
GND
DIO7
DIO6
DIO5
DIO4

CH4/CH5 current excitation returnCH5 sensor input (–)
CH5 sensor input (+)
CH4/CH5 2 sensor common
CH4/CH5 4-wire, 2 sensor common
CH4 sensor input (–)
CH4 sensor input (+)
No connection
CH4/CH5 current excitation source+5V output
GroundDIO channel 7
DIO channel 6
DIO channel 5
DIO channel 4

Declaration of Conformity
Manufacturer:
Address:

Category:

Measurement Computing Corporation
10 Commerce Way
Suite 1008
Norton, MA 02766
USAElectrical equipment for measurement, control and laboratory use.

Measurement Computing Corporation declares under sole responsibility that the product

WLS-TEMP
to which this declaration relates is in conformity with the relevant provisions of the following standards or otherdocuments:
EU EMC Directive 89/336/EEC: Electromagnetic Compatibility, EN 61326 (1997) Amendment 1 (1998)
Emissions: Group 1, Class B
EN 55011 (1990)/CISPR 11: Radiated and Conducted emissions.

Immunity: EN61326, Annex AIEC 61000-4-2 (1995): Electrostatic Discharge immunity, Criteria C.
IEC 61000-4-3 (1995): Radiated Electromagnetic Field immunity Criteria A.
IEC 61000-4-8 (1994): Power Frequency Magnetic Field immunity Criteria A.

ETSI EN301 489-1 (2004)
IEC 61000-3-2 (2001) Harmonic Current Emissions, IEC 61000-3-3 (2003) Voltage Fluctuations and Flicker
Emissions: Group 1, Class B

CISPR 22 (2004): Radiated and Conducted Electromagnetic Emissions (USB cable with ferrite suppressor
assembly required).
IEC 61000-3-2 (2001): Harmonic Emissions Class A
IEC 61000-3-3 (2003): Fluctuations and Flicker

Immunity:







IEC 61000-4-2 (2001): Electrostatic Discharge immunity, Criteria C.
IEC 61000-4-3 (2002): Radiated Electromagnetic Field immunity Criteria A.
IEC 61000-4-4 (2004): Electric fast transient burst immunity Criteria B.
IEC 61000-4-5: Fast surge immunity Criteria B
IEC 61000-4-6 (2003): Radio Frequency Common Mode immunity Criteria B*.
IEC 61000-4-11 (2004): Voltage dips and interrupt immunity Criteria B* There may be a loss of performance in the presence of an RF electromagnetic disturbance on the input/output
ports. Performance loss will be limited to measured temperatures outside of specified accuracy. The transmitter/ receiver will continue to operate as specified. Stored data and operating state will be maintained during the
disturbance. Operation will recover to within specified limits after the disturbance is removed.
Declaration of Conformity based on tests conducted by Chomerics Test Services, Woburn, MA 01801, USA in
November, 2006. Test records are outlined in Chomerics Test Report #EMI4660.06.
We hereby declare that the equipment specified conforms to the above Directives and Standards.

Carl Haapaoja, Director of Quality Assurance

Measurement Computing Corporation
10 Commerce Way
Suite 1008
Norton, Massachusetts 02766(508) 946-5100
Fax: (508) 946-9500
E-mail: info@mccdaq.com
www.mccdaq.com