Measurement Computing USB-5203 User Manual

USB-5203

User's Guide

Multi-sensor Measurement and Data Logger

Document Revision 15
July 2015
© Copyright 2015

HM USB-5203.docx

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2

Table of Contents

Preface

About this User’s Guide ....................................................................................................................... 5

What you will lear n from this user's guide ......................................................................................................... 5

Conventio ns in this user's guide ......................................................................................................................... 5

Where to find more information ......................................................................................................................... 5

Chapter 1

Introducing the USB-5203 .................................................................................................................... 6

Logging data with the USB-5203 ..................................................................................................................................... 6

Functional block diagram ................................................................................................................................... 7

Chapter 2

Installing the USB-5203 ........................................................................................................................ 8

Unpacking........................................................................................................................................................... 8

Installing the software ........................................................................................................................................ 8

Installing the hardware ....................................................................................................................................... 8

Firmware revision 2.12 and earlier ................................................................................................................................... 8

Firmware revision 3.0 and later ........................................................................................................................................ 8

Configuri ng the hardware ................................................................................................................................... 9

Configuring data logging options...................................................................................................................................... 9

Calibrating the hardware..................................................................................................................................... 9

Factory calibration ............................................................................................................................................................ 9

Field-calibration ................................................................................................................................................................ 9

Chapter 3

Sensor Connections ........................................................................................................................... 10

Screw terminal pinout ....................................................................................................................................... 10

Sensor input terminals (C0H/C0L to C7H/C7L) ..............................................................................................................10

Current excitation output terminals (±I1 to ±I4) ..............................................................................................................11

Four-wire, two sensor common terminals (4W01 to 4W67) ............................................................................................11

Two sensor common terminals (IC01 to IC67) ................................................................................................................11

Digital terminals (DIO0 to DIO7) ....................................................................................................................................11

CJC sensors ......................................................................................................................................................................11

Power terminals (+5V ) .....................................................................................................................................................11

Ground terminals (GND) .................................................................................................................................................11

Thermocouple connections ............................................................................................................................... 11

Wiring configuration ........................................................................................................................................................12

RTD and thermistor connections ...................................................................................................................... 12

Two-wire configuration ...................................................................................................................................................13

Three-wire configuration .................................................................................................................................................14

Four-wire configuration ...................................................................................................................................................14

Semiconductor sensor measurements ............................................................................................................... 15

Wiring configuration ........................................................................................................................................................15

Digital I/O connections ..................................................................................................................................... 16

Configuring the DIO channels to generate alarms ...........................................................................................................16

Chapter 4

Functional Details ............................................................................................................................... 17

Thermocouple measurements ........................................................................................................................... 17

Cold junction compensation (CJC) ..................................................................................................................................17

Data linearization .............................................................................................................................................................17

Open-thermocouple dete c t io n (OTD) ..............................................................................................................................17

RTD and thermistor measurements .................................................................................................................. 18

Data linearization .............................................................................................................................................................18

3

USB-5203 User's Guide

External components ........................................................................................................................................ 18

Screw terminals................................................................................................................................................................18

USB connector .................................................................................................................................................................19

LED .................................................................................................................................................................................19

CompactFlash® memory card slot ....................................................................................................................................19

Data logging button .........................................................................................................................................................20

External power supply ...................................................................................................................................... 21

Disconnect ing the USB-5203 from the computer ............................................................................................. 21

Transferring binary data after a logging session ............................................................................................... 21

Converting binary data after a logging session ................................................................................................. 21

Chapter 5

Specifications ...................................................................................................................................... 22

Analog input ..................................................................................................................................................... 22

Channel configurations ..................................................................................................................................... 22

Compatible sensors ........................................................................................................................................... 23

Accuracy ........................................................................................................................................................... 23

Thermocouple measurement accuracy .............................................................................................................................23

Semiconductor sen s or measurement accuracy .................................................................................................................24

RTD measurement accuracy ............................................................................................................................................24

Thermistor measuremen t accuracy ..................................................................................................................................25

Throughpu t rate to PC ...................................................................................................................................... 26

Digital input/output........................................................................................................................................... 26

Temperature alarms .......................................................................................................................................... 26

Memory ............................................................................................................................................................ 27

Microcontroller ................................................................................................................................................. 27

Data Logging .................................................................................................................................................... 27

Real time clock ................................................................................................................................................. 28

USB +5V vol tage ............................................................................................................................................. 28

Power ................................................................................................................................................................ 28

USB specifications ........................................................................................................................................... 29

Current excitation outputs (Ix+) ....................................................................................................................... 29

Environmental .................................................................................................................................................. 30

Mechanical ....................................................................................................................................................... 30

Screw terminal connector ................................................................................................................................. 30

Declaration of Conformity .................................................................................................................. 31

4

About this User’s Guide

What you will learn from this user's guide

This user's guide descri bes the Measurement Comput ing USB-5203 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 wor d or phrase.

Preface

Where to find more informati on

Additional information about USB-5203 hardware is available on our website at www.mccdaq.com. You can
also contact Measurement Computi ng Corporation with specific questions.

 Knowledgebase: kb.mccdaq.com
 Tech support form: www.mccdaq.com/support/support_form.aspx
 Email: [e-mail]
 Phone: [phone] and follow the instructions for reaching Tech Support

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

.

5

Chapter 1

Introducing the USB-5203

The USB-5203 provi des eight differential input channels that are software-programmable for different sensor
categories including thermocouple, R TDs, thermistors, and semiconductor sensors.

Eight indep endent, TTL-compatible d igital I /O c hannels are provided to monitor TTL-level inputs,
communicate with external devices, and to generate alarms. The digital I/O channels are software­programmable for input or output.

With the USB-5203, you can take measurements from four sensor categories:

 Thermocouple – types J, K, R, S, T, N, E, and B
 Resistance temperature detectors (RTDs) – 2, 3, or 4-wire measurements of 100 Ω platinum RTDs
 Thermistors – 2, 3, or 4-wire measurements
 Semiconductor temperature sensors – LM36 or equivalent

The USB-5203 provides a 24-bit analog-to-digital (A/D) converter fo r e a c h p a ir 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 cannot mix categories among the
channels that constitute a channel pair (although it is permissible to mix thermocouple types).

The USB-5203 provides two integrated cold junction compensation (CJC) sensors for thermocouple
measurements, and built -i n current excitation sources for resistive sensor measurements.

An open thermocouple detection feature lets you detect a broken thermocouple. An on-board microprocessor
automatically linearizes the measurement data according to the sensor category.

The USB-5203 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.

®

You can log your sensor measurements to a CompactFlash
volatile storage device. A 512 MB CompactFlash memory card is shipped with the device to store your data.
For more information, refer to Logging data with the USB-5203 below.

The USB-5203 device is compatible with both USB 1.1 and USB 2.0 ports. The speed of the device may be
limited when using a USB 1.1 port due to the difference in transfer rates on the USB 1.1 versions of the
protocol (low-speed and full-speed).

External power is required for data loggin g o perations

Due to processing limitations, you cannot log data to the memory card when the USB-5203 is connected to your
computer's active USB bus. When operating as a data logger, disconnect the USB cable from the computer, and
connect the external power supply shipped with the device.

The USB-5203 is a standalone plug-and-play device. External power is required for data logging mode only. All
configurable options are software programmable. The USB-5203 is fully software calibrated.

memory card. CompactFlash is a removable non-

Logging data with the USB-5203

Due to processing limitations, you cannot log data to the memory card when the USB-5203 is connected to an
active USB port. When operating as a data logger, disconnect the USB cable from the computer, and connect
the external power supply shipped with the device.

The USB-5203 has many software-selectable options for setting up data logging.
You can record:

 temperature (° C) or raw data from selected input channels
 timestamp data
 CJC sensor rea dings

6

USB-5203 User's Guide Introducing the USB-5203

You can specify the number of seconds between samples. You can begin logging data at power up, when you
press the data logging button, or at a specific date and time.

Data is stored on the memory card in b inary files. After logging measurements, yo u can transfer the files to your
computer. You can use InstaCal to convert the files to
format for use in other applications.

.csv format for use in Microsoft Exc e l files, or to .txt

Functional block diagram

USB-5203 functions are illustrated in the block diagram shown here.

Figure 1. Functional block diagr am

7

Chapter 2

Installing the USB-5203

Unpacking

As with any electronic device, you should take care while handling to avoid damage from static
electricity. Before removing the device from its p ackaging, ground yourself using a wrist strap or by si mply
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 MCC DAQ Quick Start for instructions on installing the software on the MCC DAQ CD. Refer to
the device product page o n the Measurement Computing website for information a bout the included and
optional software supported by the USB-5203.

Install the software before you install your device

The drive r needed to run the USB-5203 is installed with the software. Therefore, you need to install the
software package you plan to use before you install the hardware.

Installing the hardware

To connect t he USB-5203 to your syst em, turn your c omputer 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 USB-5203.

If you are connecting the USB-5203 to an external self-powered hub, connect the USB hub to the computer
before you connect the device to the hub. This ensures that the device detects the hub as an active USB port.

Firmware revision 2.12 and earlier

When you connect the USB-5203 for the first time, a Found New Hardware dialog opens when the operating
system detects the device. When the dialog clo se s, the installation is complete. The device
then remain on. This indicates that communication is established between t he USB-5203 and your computer.

Firmware revision 3.0 and later

The USB-5203 installs as a composite device with separate devices attached. When you connect the USB-5203
for the first time, a

It is normal for multiple dialogs to ope n when you connect the USB-5203 for the first time. For additional
information, refer to the "Notes on installing and using the USB-5201 and USB-5203 data logging devices" that
ships with t he device.

When the last dialog closes the installation is complete. The LED on the USB-5203 will blink and then remain
on. This indicates that communication is established between the USB-5203 and your computer.

Caution! Do not disconnect any device from the USB bus while the computer is communicati ng with the

Found New Hardware dialog opens as each USB-5203 interface is detected.

USB-5203, or you may lose data and/or your ability to communicate with the USB-5203.

LED will blink and

If the LED turns off

If the LED is lit but then turns off, the computer has lost communication with the USB-5203. To restore
communication, disconnect the USB cable from the computer, and then reconnect it. This should restore
communication, and the LED should turn back on.

8

USB-5203 User's Guide Installing the USB-5203

Configuring the hardware

All hardware configuration options on the USB-5203 are software-selectable. The configurable options
dynamically update according to the selected sensor category. All hardware configuration options on the USB­5203 are software-selectable. Settings are stored on an isolated microcontroller in EEPROM – which is non­volatile memory on the USB-5203 – and are loaded on power-up.

Default configuration

The factory default sensor type confi guration is Disabled. The disabled mode disconnects the analog i nputs
from the terminal blocks and internally grounds all of the A/D inputs. This mode also disables each of the
current excitation sources.

Warm up

Allow the USB-5203 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.

Configuring data logging options

The following data logging options are programmable with software.

 select the input channels to log
 set the data format
 set the start mode
 set up alarm conditions
 copy and convert saved binary files
 delete data files

All data logging options are stored on the USB-5203 in non-volatile memory in EEPROM, and are loaded on
power up.

Calibrating the hardware

Factory calibration

The Measurement Computing Manufacturing Test department performs the initial factory calibration. Return
the device to Measurement Computing Corporation when calibration is required. The recommended calibration
interval is one year.

Field-calibration

The USB-5203 supports field-ca libration with InstaCal. Calibrate the device whenever the ambient temperature
changes by more than ±10 °C from the last self-calibration.

Allow the USB-5203 to operate for at least 30 minutes before calibrating.

9

Chapter 3

Sensor Connections

The USB-5203 supports the following temperature sensor types:

 Thermocouple – types J, K, R, S, T, N, E, and B
 Resistance temperature detectors (RTDs) – 2, 3, or 4-wire measurement modes of 100 Ω platinum RTDs.
 Thermistors – 2, 3, or 4-wire measurement modes.
 Semiconductor temperature sensors – LM36 or equivalent

Sensor selection

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

Screw terminal pinout

The USB-5203 has four rows of screw terminals – two rows on the top edge of the housing, and two rows on
the bottom edge. Each row has 26 connections. Between each bank of screw terminals are two integrated CJC
sensors used for thermocouple measurements. Signals are identified in Figure 2.

Figure 2. USB-5203 screw terminal pin numbers

Use 16 AWG to 30 AWG wire for your signal connections.

Tighten screw terminal connections

When making connections to the screw terminals, fully tighten the screw. Simply touching the top of the screw
terminal is not sufficient to make a pr oper connection.

Sensor input terminals (C0H/C0L to C7H/C7L)

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 withi n channel pairs. It is permitted to mix thermocouple types (J, K, R, S, T, N,
E, and B) wit hin channel pa irs, however.

10

USB-5203 User's Guide Sensor Connections

Do not connect two different sensor categories to the same channel pair

The USB-5203 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 terminals (±I1 to ±I4)

The USB-5203 has four dedicated pairs of current excitation output terminals (±I1 to ±I4). These terminals ha ve
a built-in precision current source to provide excitation for the resistive sensors used for RTD a nd thermistor
measurements.

Each current excitation terminal is d e dicated to one pair of sensor input channels:

 I1+ is the current excitation source for cha nnel 0 and channel 1
 I2+ is the cur rent excitation source for channel 2 and channel 3
 I3+ is the cur rent excitation source for channel 4 and channel 5
 I4+ is the cur rent excitation source for channel 6 and channel 7

Four-wire, two sensor common terminals (4W01 to 4W67)

These terminals are used as the common connection for four-wire configurations with two RTD or thermistor
sensors.

Two sensor common terminals (IC01 to IC67)

These terminals are used as the common connection for two-wire con figurations with two RTD or thermistor
sensors.

Digital terminals (DIO0 to DIO7)

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

If a digital bit is set up as an alarm, the bit is configured for output on power-up, and assumes the state defined
by the alarm configuration.

CJC sensors

The USB-5203 has t wo built in high-resolution temperature sensors. One sensor is located on the right side of
the package, and one sensor is located on the left side.

Power terminals (+5V)

The two +5V output terminals are isolated (500 VDC) from the USB +5V.
Caution! Each +5V terminal is an output. Do not connect to an external power supply to these terminals or

you may dama ge the USB-5203 and possibly the computer.

Ground terminals (GND)

The 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

The USB-5203 makes f ul ly-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 so ftware. 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.

11

USB-5203 User's Guide Sensor Connections

Wiring configuration

Connect the thermocouple to the USB-5203 using a differential configuration, as shown in Figure 3.

Figure 3. Typical thermocouple connection

The USB-5203 GND pins are isolated from earth ground, so connecting thermocouple sensors t o voltages
referenced to earth ground is permissible as long as the isolation between the GND pins (9, 19, 28, 38) and earth
ground is maintained.

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 i nsulated or ungrounded
thermocouples when possible.

Maximum input voltage between analog input an d ground

The absol ute maximum inp ut voltage between an analog input and the isolated GND pins is ±24 VDC when the
USB-5203 is powered on or 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 temper a tur e – thermistors show a large change in resistance that is proportional to a
small 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 require an excitation current to produce a voltage drop that can
be measured differentially across the sensor. The device has four built-in current excitation sources (±I 1 to ±I4)
for measuring resistive type sensors. Each current excitation terminal is dedicated to one channel p air.

The USB-5203 makes two, three, and four-wire measur ements of RTDs (100 Ω platinum type) and thermistors.
Use InstaCal to select the sensor type and the wiring configuration. Once the resistance value is calculated, the

value 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.

RTD maximum resistance

Resistance values greater than 660 Ω cannot be measured in 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.

Thermistor maximum resistance

Resistance values greater than 180 kΩ cannot be measured in thermistor mode. The 180 kΩ resistance limit
includes the total resistance ac ross the current excitation (±Ix) pins, which is the sum of the thermistor
resistance and the lead resistance.

12

USB-5203 User's Guide Sensor Connections

Two-wire configura tion

The easiest way to connect an RTD sensor or thermistor to the USB-5203 is with a two-wire configuration,
since it requi res the fewest connections t o the sensor. With this method, the two wires that pr ovide the RTD
sensor with its excitation current also measure the voltage across the sensor.

Since RTDs exhibit a low nominal resistance, measurement accuracy can be affected due to the lead wire
resistance. For example, connecting lead wires that have a resistance of 1 Ω (0.5 Ω each lead) to a 100 Ω
platinum RTD will result 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 sin gle-sensor measurement configuration is s hown in Figure 4.

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

When you select a two-wire single sensor configuration with InstaCal, connections to C#H and C#L are made
internally.

Two-wire, two sensor

A two-wire, two-s ensor 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) and
C#H/C#L (second sensor) are made internally.

When confi gured for two-wire mode, both sensors must be connected to obtain proper measurements.

13

USB-5203 User's Guide Sensor Connections

Three-wire configuration

A three -wire configuration compensates for lead-wire resistance by using a single-voltage sense conne ction.
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 thermi stor sen sor mea sur eme nt conf igur a tio n

When you select a three-wire sensor configuration with InstaCal, the USB-5203 measures the lead resistance on
the first channel (C#H/C#L) and measures the sensor itself using the second channel (C#H/C#L). This
configuration 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.

Three-wire compensation

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 configuratio n when your application requires very hi gh accuracy
measurements. Examples of a four-wire single-sensor measurement configuration are shown in Figure 7 and
Figure 8.

You can configure the USB-5203 with either a single-sensor-per-channel, or a two-sensor–per-channel pair.

Four-wire, single-sensor

A four-wir e, single-sensor connected to the first channel of a channel pair is shown in Figure 7.

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

A four-wir e, single-sensor connected to the second channel of a channel pair is shown in Figure 8.

14

USB-5203 User's Guide Sensor Connections

Figure 8. Four-wire, single RTD or thermistor sensor measurement configuration

A four-w ire, two-sensor measurement configuration is show n in Figure 9.

Figure 9. Four-wire, two RTD or thermistor sensors measurement configuration

When confi gured for two-wire 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 to
thermocouples and RTDs. However, semiconductor sensors can be accurate, inexpensive and easy to interface
with other electronics for display and control.

The USB-5203 makes high-resolution measurements of semiconductor sensors. The softw are outputs the
measurement data as a 32-bit floating point value in either voltage or temperature.

Use InstaCal to select the sensor type (LM35, TMP35 or equivalent) and the sensor input channel to connect the
sensor.

Wiring configuration

Connect the semiconductor sensor to the USB-5203 using a single-ended configur ation, as shown in Figure 10.
The device provides

+5V and GND pins for powering the sensor.

Figure 10. Semiconductor sensor measurement configuration

15

USB-5203 User's Guide Sensor Connections

Digital I/O connections

You can connect up to eight digital I/O lines to the screw terminals labeled DIO0 to DIO7. All digital I/O lines
are pulled up to +5V with a 47 kΩ resistor (default). You can request the factory to configure the resistor for
pull-down to ground if desired. You can configure each digital bit for eithe r input or output.

Caution! If a digital bit is set up as an alarm, the bit will be configured for output on power-up, and assume

the state defined by the alarm configuration.

When you configure the di gital bits for i nput, you can u s e the USB-5203 digital I/O terminals to detect the state
of any TTL-level input. Refer to the schematic shown in Figure 11. If you set the switch to the +5V input, DIO0
reads TRUE (1). If you move the switch to GND, DIO0 reads FALSE (0).

Figure 11. Schematic showing switch detection by digital channel DIO0

Caution! All ground pins on the USB-5203 (pins 9, 19, 28, 38) are common and are isolated from earth

ground. If a c onnection 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 regard ing 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 USB-5203 features eight independent temperature alarms. All alarm options are software configurable.
When a digital bit is configured a s an alarm, that bit will be configured as an output on the next power cycle and

assume 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 the

temperature input channels. You set up the temperature conditions to activate an alarm, and the o utp ut s ta te of
the channel (active high or low) when activated. When an alarm is activated, its associated DIO channel is
driven to the output state specified.

The alarm configurations are stored in non-volatile memory and are loaded on power up. The temperature
alarms function both in data logging mode and while attached to the USB port on a computer.

16

Chapter 4

Functional Det ails

Thermocouple measure m ents

A thermocouple consists of two dissimilar metals that are joined together at one end. When the junction of the
metals is heated or cooled, a voltage is produced that correlates to temperature.

The USB-5203 hardware level-shifts the thermocouple’s outp ut 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 USB-5203 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 USB­5203 terminal blocks produce an additional thermocouple junction. This junction creates a small voltage error
term which must be re moved from the overall sensor measurement using a cold junction compensation
technique. The measured voltage includes both the thermocoup le voltage and t he cold junct i on voltage. To
compensate for the additional cold junction voltage, the USB-5203 subtracts the cold junction voltage from the
thermocouple voltage.

The USB-5203 has t wo high-resolution temperature sen so rs that are integrated into the design of the USB-5203.
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 be calculated. A
software algorithm automatically corrects for the additional thermocouples created at the terminal blocks by
subtracti ng the calculated cold junction voltage fr om the analog i nput'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 on-board microcontroller automatically
linearizes 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 config ure d format (voltage or
temperature).

Open-thermocouple detection (OTD)

The USB-5203 is equipped with an open-thermocouple detection for each analog input channel. 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, 105 nA (max.) of input leakage current is i njected into the
thermocouple. This current can cause an error voltage to develop across the lead resistance of the thermocouple
that is indistinguishabl e from the thermocouple vol tage you ar e measuring. You can estimate this error voltage
with the following formula:

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 wire
by using a wire with a larger diameter. With open-thermocouple detection disabled, 30 nA (max) of input
leakage current is injected into the thermocouple.

17

USB-5203 User's Guide Functional Details

1

Screw terminal pins 1 to 26

4

Data logging button

2

Screw terminal pins 27 to 52

5

CompactFlash® memory card slot (with card)

3

LED 6 USB connector

RTD and thermistor measure m e nt s

RTDs and thermistors are resistive devices that require an excitation current to produce a voltage drop that can
be measured differentially across the sensor. The USB-5203 measures the sensor resistance by forcing a known
excitatio n current through the sensor and then measuring (differentially) the voltage across the sensor to
determine its resistance.

After the voltage measuremen t is made, the resistance of the RTD is calculated using Ohms law – the sensor
resistance is calculated by divid ing the measured voltage by the current excitation level (±
of 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 temperat ure value. The
measurement is returned by software as a 32-bit floating point value in a voltage, resistance o r temperature
format.

Data linearization

An on-board 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 the

coefficients from the sensor manufacturer's data sheet).

Ix) source. The value

External components

The USB-5203 has the following exte rnal components, as shown in Figure 12.

Screw terminals

Use the screw terminals for connecting temperature sensors and digital I/O lines. These terminals also provide
ground and power output connections. Refer to the "Sensor Connections" chapter for screw terminal
descriptions.

Figure 12. External component locations

18

USB-5203 User's Guide Functional Details

Steady green

The USB-5203 is connected to a compu ter or external USB hub.

Blinks continuously

Data is being transferred.

installation).

Blinks several times

Initial communication is established b etween the USB-5203 and the computer.

Off

The USB-5203 is not connected to an active USB port.

Logging off

The LED is off.

The USB-5203 is not logging data, and/or

Start Logging on Power
Up

The LED turns on when ext ernal power is
connected, then blin ks each time data is captured.

Blinks when logging data.

Start Logging on Button

Start Logging at

The LED is off – blinks on once per second until

Blinks on once per second until speci fied

Any logging mode

Blinks rapidly (250 ms period) and continuously.

The memory card is full.

USB connector

When not lo gging data, connect the USB cable to a USB port on your computer or to a n external USB hub that
is connected to your computer. When connected to an active USB bus, the USB connector provides +5 V power
and commu n ication. The volta ge supplied through the USB c onnector is system-dependent, and may be less
than 5 V. No external power supply is required.

Due to processing limitations, you cannot log data when the device is attached to an active USB bus. For data
logging operations, connect the USB connector to the external power supply.

LED

The LED uses up to 5 mA of cur rent. The function of the LED varies according to whethe r the USB-5203 is
connected to an active USB port, or when the device is logging data and connected to the external power
supply.

Refer to the table below for the functio n o f the USB-5203 LED when the device is connected to an active USB
port and not logging data.

LED function when the USB-5203 is connected to an active USB port

LED Illumination Indication

Upon connection, the LED should flash a few times and then remain lit (indicates a successful

Refer to the table below for the functio n o f the USB-5203 LED when the device is connected to the external
supply and is logging data. The function of the LED varies according to the selected logging mode.

LED function when the USB-5203 is logging data

Logging mode LED Illumination Indication

the device is not powered

Specified Time

The LED stays off until the data logging button is
pressed and held for approximately 1 second. At
that time, the LED turns on and blinks each time
data is captured.

the specified date/time to start logging is reached.
At that time, the LED turns on – blinks off each
time data is captured.

Blinks when logging data.

data/time to log data occurs. Then it turns
on and blinks each time data is captured.


 The memory card was removed during

logging. Insert the memory card again
to stop the device blinking.

CompactFlash® memory card slot

The CompactFlash slot accepts standard memory cards. A 512 MB memory card is shipped with the device. For
extensive data logging, you can insert a higher capacity card of up to 2 GB. You must format the memory card
before logging data for the first time.

19

USB-5203 User's Guide Functional Details

 time = total disk time in seconds

 R = logging rate in seconds

enabled

Calculating the logging time for a memory card

Use the following formula to calculate the approximate amount of logging time in seconds that one of the
supported memory card allows. The USB-5203 supports 512 MB , 1 GB, and 2 GB CompactFlash memory
cards.

where

 N
 N
 n

= size of memory card in bytes

Disk

= 1 byte for digital I/O

DIO

= number of channels logged

Channels

 NTS = 6 bytes for timestamp, if enabled
 N
 N

= 4 bytes for a temperature reading

Temp

= 8 bytes if CJC sensor readings a re

CJC

The following table provides example s of logging one channel and eight channels of t emperature readings at the
max logging rate of 1 S/s to a 512 MB memory card with DIO, timestamp, and CJC sensor logging enabled:

Memory card

(bytes)

DIO enabled Number of

channels

Logging

rate (S/s)

Timestamp

enabled

Temperature

reading

CJC

enabled

512,000,000 1 1 1 6 4 8

512,000,000 1 8 1 6 4 8

Data logging button

Use the data logging button t o end a data l ogging sessio n. The data logging button is al s o used to star t recording
data when the logging mode is set in In staCal to Start Logging on Button.

 To begin recording data, press and hold the button until t he LED begins to blink. The first sample is taken

one second after the LED illuminates.
When you first power on the USB-5203, wait at least five seconds before pressing the data logging button.

To achieve rated accuracy, allow the USB-5203 to warm up for 30 minutes before logging data.

 To stop recording data, press and hold the button again until the LED is off.
Caution! To prevent l oss of data, always use the button to stop logging. Make sure the data is written to the

memory card before you disconnect the device from the power source.
The device caches log data in volatile memory prior to writing to the memory card.
Pressing the data logging button has no effect when the USB-5203 is connected to an active USB port and not

logging data.

External power required for data logging

Due to processing limitations, data logging is not allowed when the USB-5203 is attached to an active USB bus.
The USB-5203 must be connected to the standalone power supply to perform data logging.

20

USB-5203 User's Guide Functional Details

External power supply

The external power supply is a 2.5 W USB power adapter used to power the device during data logging
operations.

Disconnecting the USB-5203 fr om the comput e r

You don't need to shut down your computer to disconnect the USB-5203. Refer to the instructions below when
disconnecting the USB-5203 from your computer's USB port.

When the USB-5203 is installed with firmware revision 3 or later and you are running Windows XP, use the
Unplug or Eject icon on the computer's taskbar to safely stop the USB-5203 before you unplug it. To do this,
right-click on the icon, select the USB-5203 and click
disconnect the device from your computer.

Stop. Windows will notify you when it is safe to

Transferring binary data af t e r a logging session

Data is stored on the memory card in b inary files. After logging measurements, yo u can transfer the files to your
computer by reconnecting the USB-5203 to a USB port on your computer or by removing the Compac tFlash
card from the USB-5203 and using a card reader connected to your computer.

Note that when installed with firmware version 3 and later the USB-5203 appears as a Mass Storage Device
when connected to a USB port on your computer, so you can copy files using Windows Explorer.

Converting binary data aft e r a logging s e s s ion

If your USB-5203 is connected to a USB port on your computer, you can use InstaCal or TracerDAQ to convert
the files on the CompactFlash card to .CSV format for use in Microsoft Excel files, or to .TXT format for use in
other applications.

If you transferred binary files to your computer hard drive or removed the CompactFlash card from your
USB-5203 and are using a card reader connected to your computer, use TracerDAQ to import the files and save
them as
connected to your computer.

.csv or.txt format. InstaCal can only convert files when the CompactFlash card is in a USB-5203

21

A/D converters

Four dual 24-bit, Sigma-Delta type

Number of channels

8 differential

Input isolation

500 VDC minimum between field wiring and USB
interface

Channel configuration

Software programmable to match sensor type

Differential input voltage

Thermocouple

±0.080 V

Thermistor

0 V to 2 V

Semiconductor sensor

0 V to 2.5 V

Absolute maximum input

±C0x through ±C7x relative to GND

±24 V power on, ±24 V power off
Input impedance

5 GΩ, min

Input leakage current
Open thermocouple detect disabled

30 nA max
Open thermocouple detect enabled

105 nA max

Normal mode rejection ratio

fIN = 60 Hz

90 dB min

Common mode rejection

fIN=50 Hz/60 Hz

100 dB min
Resolution

24 bits

No missing codes

24 bits

Input coupling

DC

Warm-up time

30 minutes min

Open thermocouple d etect

Automatically enabled when the channel pair is

CJC sensor accuracy
15 °C to 35 °C

±0.25 °C typ,±0.5 °C max

0 °C to 70 °C

–1.0 °C to +0.5 °C max

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 Conditions Specification

Chapter 5

range for the various sensor
categories

voltage

Ratio

RTD 0 V to 0.5 V

Channel configurations

configured for thermocouple sensor.
The maximum open detecti on time is 3 seconds.

Internally, the device has four, dual-c han nel, fully differential A/Ds providing a total of eight differential
channels. The analog input channels are therefore c onfigured 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 confi gured to monitor 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.

Channel configuration information is stored in the EEPROM of the isolated micr ocontroller by the firmware
whenever any item is modified. Modification is performed by commands issued over USB from an external
application, and the configuration is made non-volatile through the use of the EEPROM.

22

USB-5203 User's Guide Specifications

Disabled (Note 1)

Thermocouple

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

8 differential chann els

Semiconductor sensor

8 differential chann els

2-wire input configuration with two sensors per channel pair

8 differential chann els

3-wire configuration with a single sensor per channel pair

4 differential chann els

4-wire input configuration with a single sensor per channel pair

4 differential chann els

4-wire input configuration with two sensors per channel pair

8 differential chann els

Thermocouple

J: –210 to 1200

K: –270 to 1372

R: –50 to 1768

S: –50 to 1768

T: –270 to 400

N: –270 to 1300

E: –270 to 1000

B: 0 to 1820

RTD

100 Ω PT (DIN 43760: 0.00385 ohms/ohm/°C)

100 Ω PT (SAMA: 0.003911 ohms/ohm/°C)

Thermistor

Standard 2,252 Ω through 30,000 Ω

Semiconductor / IC

LM35, TMP35 or equivalent

Table 2. Channel configuration specifications

Sensor Category Conditions Max number of

sensors (all channels
configured alike)

RTD and thermistor 2-wire input configuration with a single sensor per channel pair 4 differential chann els

Note 1: The factory default configuration is Disabled. In Disabled mode, analog inputs are disconnected from

the terminal blocks and all of the A/D inp uts are internally grounde d. This mode also disables each of
the current excitation sources.

Compatible sensors

Table 3. Compatible sensor type specifications

Parameter Specification (°C)

100 Ω PT (ITS-90/IEC751:0.00 3 850 5 ohms/ohm/°C)

Accuracy

Thermocouple measurement accuracy

Thermocouple measurement accuracy specifications include linearization, cold-junction compensation and
system noise. These specs are for one year, or 3000 operating hours, whichever c omes first, and for operat ion of
the device betwee n 15 °C and 35 °C. For measurements outside this range, add ±0.5° 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.

Thermocouples must be connected to the device such that they are floating with respect to GND. 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.

When thermocouples are attached to conductive surfaces, the voltage differential between multiple
thermocouples must remain within ±1 .4 V. For best results, MCC recommends using insulated or ungrounded
thermocouples when possible.

23

USB-5203 User's Guide Specifications

J
±1.499

±0.507

–210 to 0

±0.643

±0.312

0 to 1200

K
±1.761

±0.538

–210 to 0

±0.691

±0.345

0 to 1372

S
±2.491

±0.648

–50 to 250

±1.841

±0.399

250 to 1768.1

R
±2.653

±0.650

–50 to 250

±1.070

±0.358

250 to 1768.1

B
±1.779

±0.581

250 to 700

±0.912

±0.369

700 to 1820

E
±1.471

±0.462

–200 to 0

±0.639

±0.245

0 to 1000

T
±1.717

±0.514

–200 to 0

±0.713

±0.256

0 to 600

N
±1.969

±0.502

–200 to 0

±0.769

±0.272

0 to 1300

LM35, TMP35 or equivalent

–40 to 150

±0.50

PT100, DIN, US

–200 to –150

±2.85

±2.59

–150 to –100

±1.24

±0.97

–100 to 0

±0.58

±0.31

0 to 100

±0.38

±0.11

100 to 300

±0.39

±0.12

300 to 600

±0.40

±0.12

Table 4. Thermocouple accuracy specifications, including CJC measurement error

Sensor Type Maximum error (°C) Typical error (°C) Temperature range (°C)

Semiconductor sensor measurement accuracy

The error s hown in Table 5 below does not include errors of the sensor itself. These specs are for one year while
operation of the device is between 15 °C and 35 °C. Please contact your sensor supplier for details on the actual
sensor error limitations.

Table 5. Semiconductor sensor accuracy specifications

Sensor Type Temperature Range (°C) Maximum Accuracy Error (°C)

RTD measurement accuracy

The error s hown in Table 6 below 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 operating
the device 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.

In RTD mode, the device cannot measure resistance values greater than 660 Ω. The 660 Ω resistance limit
includes the total resistance across the current excitation (Ix+/Ix–) pins, which is the sum of the RTD resistance
and the lead resistances.

For accurate three-wire compensation, the individual lead resistances connected to the Ix+/Ix– pins must be of
equal value.

Table 6. RTD measurement accuracy specifications

RTD Sensor

Temperature (°C)

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

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

or ITS-90

24

USB-5203 User's Guide Specifications

2252 Ω

–40 to120

±0.05

3000 Ω

–40 to120

±0.05

5000 Ω

–35 to120

±0.05

10000 Ω

–25 to120

±0.05

30000 Ω

–10 to120

±0.05

–40

76 kΩ

101 kΩ

168 kΩ

240 kΩ

885 kΩ

–35

55 kΩ

73 kΩ

121 kΩ

179 kΩ

649 kΩ

–30

40 kΩ

53 kΩ

88 kΩ

135 kΩ

481 kΩ

–25

29 kΩ

39 kΩ

65 kΩ

103 kΩ

360 kΩ

–20

22 kΩ

29 kΩ

49 kΩ

79 kΩ

271 kΩ

–15

16 kΩ

22 kΩ

36 kΩ

61 kΩ

206 kΩ

–10

12 kΩ

17 kΩ

28 kΩ

48 kΩ

158 kΩ

–5

9.5 kΩ

13 kΩ

21 kΩ

37 kΩ

122 kΩ

0

7.4 kΩ

9.8 kΩ

16 kΩ

29 kΩ

95 kΩ

Thermistor measurement accuracy

The error s hown in Table 7 below 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 operating the
device between 15 °C and 35 °C. The specification does not include lead resistance errors for 2-wire thermistor
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 kΩ (refer to Table 8 below).

Table 7. Thermistor measurement accuracy specifications

Thermistor Temperature Range (°C) Maximum Accuracy Error (°C)

= 10 µA

I

x+

Typical resistance values at various temperatures for supported thermistors are shown in Table 8 below.
The device cannot measure resistance values greater than 180 kΩ in thermistor mode. The 180 kΩ resistance

limit includes the total resistance across the current excitation (Ix+/Ix–) pins, which is the sum of the thermistor
resistance and the lead resistances.

For accurate three-wire compensation, the individual lead resistances connected to the Ix+/Ix– pins must be of
equal value.

Table 8. Typical thermistor resistance specifications

Temp
(°C)

2252 Ω

thermistor

3000 Ω thermistor 5 kΩ thermistor 10 kΩ thermistor 30 kΩ thermistor

25

USB-5203 User's Guide Specifications

1

2 Samples/second

2

2 S/s on each channel, 4 S/s total

3

2 S/s on each channel, 6 S/s total

4

2 S/s on each channel, 8 S/s total

5

2 S/s on each channel, 10 S/s total

6

2 S/s on each channel, 12 S/s total

7

2 S/s on each channel, 14 S/s total

8

2 S/s on each channel, 16 S/s total

Digital type

CMOS

Number of I/O

8 (DIO0 through DIO7)

Configuration

Independently configured for input or output.

Pull up/pull-down

All pins pulled up to +5 V via 47 kΩ resistors (default). Pull down to ground (GND) also

Digital I/O transfer rate

Digital input – 50 port reads or single bit reads per second typ
Digital output – 100 port writes or single bit writes per second typ

Input high voltage

2.0 V min, 5.5 V absolute max

Input low voltage

0.8 V max, –0.5 V absolute min

Output low voltage
(IOL = 2.5 mA)

0.7 V max
(IOH = –2.5 mA)

Number of alarms

8 (one per digital I/O line)

Alarm functionality

Each alarm controls its associated d igital I/O line as an alarm output. The input to each alarm

mode and while attached to USB.

Throughput rate to PC

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 the USB unit is
approximately 0.5 seconds.

Maximum t hroughput to a CompactFlash® memory card is 1 S/s per channel.

Table 9. Throughput rate specifications

Number of Input
Channels

Maximum Throughput

Digital input/output

Table 10. Digital input/output specifications

Parameter Specification

Power on reset is input mode unless bit is configured for alarm.

configuration

(software paced)

available.




Output high voltage

Note 2: All ground pins on the device are common and are isolated from earth ground. If a connection is made

3.8 V min

to earth ground when usin g 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.

Temperature alarms

Table 11. Temperature alarm specifications

Parameter Specification

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 function both in data logging

26

USB-5203 User's Guide Specifications

Alarm input modes

Alarm when input temperatu re > T1

T1 and T2 may be independently set for each alarm.

Alarm output modes

Disabled, digital I/O line may be u sed for normal operation

Alarm upd ate rate

1 second

EEPROM

1,024 bytes isolated micro reserved for sensor configuration

Type

Two high performance 8-bit RISC microcontrollers

Standalone power supply

USB power adapter

Memory card type

CompactFlash

Supplied memory card

512 MB CompactFlash card

Memory card host access

USB Mass Storage Device (MSD)

File systems supported

FAT16, FAT32
Log file format

binary

Logging rate

Min 1 second between ent r ies, max 232 seconds, 1 second granularity

Data items logged

Timestamp, temperature, or raw reading from selected channels, state of DIO lines, CJC
sensor readings

Logging start methods

Configurable:


 Alarm when input temperature > T1, reset alarm when input temperature goes below T2
 Alarm when input temperatu re < T1
 Alarm when input temperatu re < T1, reset alarm when input temperature goes above T2
 Alarm when input temperature is < T1 or > T2


 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)

Memory

Table 12. Memory specifications

Parameter Specification

256 bytes USB micro for external application use
256 bytes USB micro reserved for data logging configuration

Microcontroller

Data Logging

Table 13. Microcontroller specifications

Parameter Specification

Table 14. Data logging specifications

Parameter Specification

2.5 watt USB adapter with interchangeable plugs
(Includes plug for USA)

The device only creates 8.3 file names in the root subdirectory.

 Start Logging on Power Up – Logging begins 5 seconds after power on to allow

hardware to settle.

 Start Logging on Button – Device is idle on power on. Press and hold the button until

the LED turns on to begin logging. The first sample is acquired 1 second after the LED
turns on unless less than 5 seconds have elapsed since power on.

 Start Logging at Specified Time – Device is idle until the real-time clo ck i ndicates

the time is equal to or greater than th e specified time, at which time the LED turns on. The
first sample is acquired 1 second after the LED turns on unless less than 5 seconds have
elapsed since power on.

27

USB-5203 User's Guide Specifications

Logging stop methods

Stop on button press – To stop logging, press and hold the button until the LED turns off.

prior to removing power.

Logging status indication

The LED operations when connected to the AC adapter power supply are different than when

(250 ms period). Inserting a memory card stops the LED from blinking.

Accuracy

±1 minute per month

USB +5 V (VBUS) input voltage range

4.75 V min to 5.25 V max

Supply current

USB enumeration

<100 mA

Supply current (Note 3)

Continuous mode

500 mA max

+5 V output voltage range

Connected to a self-powered hub. (Note 4)

4.75 V min to

+5 V output current
(pins 21 and 47)

Connected to a self-powered hub. (Note 4)

10 mA max
Isolation

Measurement system to PC

500 VDC min

Output voltage

5 V ±5%

Output wattage

2.5W

Parameter Specification

The device caches logged data in volatile memory prior to writing to memory card. When
logging, always use the button to stop logging and ensure data is written to memory card

connected to USB.
Logging modes:

 Logging Off mode: the LED is off (disabled).
 Start Logging on Power Up mode: the LED turns on, but blinks off momentarily every

time data is captured.

 Start Logging on Button mode: the LED is initially off. When the button is pressed

and held for approximately 1 second, the LED tu rns on and act the same as Start Logging
on Power Up mode.

 Start Logging at Specified Time mode: the LED turns off, with a momentary on flash

every second until the specified date/time is reached. At that time, the LED turns on and
acts the same as Start Logging on Power Up mode.

Other indication:

 To stop logging and store the remaining data to memory card, press and hold the button

until the LED turns off. It is th en safe to remove the memory card.

 If the memory card becomes full, the LED blinks rapidly (250 ms period).
 If the memory card is removed while logging is in progress, the LED blinks rapidly

Real time clo ck

Table 15. Real time clock specifications

Parameter Specification

Battery backup CR-2032 lithium coin cell, replaceable

USB +5V voltage

Table 16. USB +5 V voltage specificat io ns

Parameter Specification

Power

Table 17. Power specifications

Parameter Conditions Specification
Connected to USB

(pins 21 and 47)

5.25 V max

AC Adapt e r Power Supply (used for data logging operation)

28

USB-5203 User's Guide Specifications

Input volt a ge

100 VAC to 240 VAC
Input current

0.2 A

USB device type

USB 2.0 (full-speed)

Device compatibility

USB 1.1, USB 2.0

USB cable type

A-B cable, UL type AWM 2725 or equivalent. (min 24 AWG VBUS/GND,
min 28 AWG D+/D–)

USB cable length

3 m (9.84 ft) max

Current excitation output

AI channel

I1+/I1–

CH0/CH1

I2+/I2–

CH2/CH3

I3+/I3–

CH4/CH5

I4+/I4–

CH6/CH7

Current excitation output ranges
Thermistor

10 µA typ

RTD

210 µA typ

Tolerance

±5% typ

Drift 200 ppm/°C

Line regulation

2.1 ppm/V max

Load regulation

0.3 ppm/V typ

Output compliance voltage

Relative to GND

3.90 V max
–0.03 V min

50 Hz to 60 Hz

Note 3: This is the total current requirement for the device which includes up to 10 mA for the status LED.
Note 4: Self-powered hub refe rs to a USB hub with an external power supply. Self-powered hubs allow a

connected USB device to draw up to 500 mA. This device may not be used with bus-powered hubs due
to 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 up o n the ma nu fac t ur er . A
laptop PC that is not connected to an external power adapter is an example of a battery-powered root
port hub.

USB specifications

Table 18. USB specifications

Parameter Specification

Device power capabili ty Self-powered, 500 mA consumption max

Current excitation outputs ( Ix+)

The device has four current excitation outputs, with I1+/I1– dedicated to the CH0/CH1 analog inputs, I2+/I2–
dedicated to CH2/CH3, I3+/I3– dedicated to CH4/CH5, and I4+/I4– dedicated to CH6/CH7. The excitation
output currents should a lways be used in this dedicate d configuration.

The current excitation outputs are automatically configured based on the sensor (thermistor or RTD) selected.

Table 19. Current excitation output specifications

Parameter Condition Specification

Configuration 4 dedicated pairs

29

USB-5203 User's Guide Specifications

Operating temperature range

0 °C to 70 °C

Storage temperature range

–40 °C to 85 °C

Humidity

0% to 90% non-condensing

Dimensions (L × W × H)

128.52 x 88.39 × 35.56 mm (5.06 × 3.48 × 1.43 ft)

Wire gauge range

16 AWG to 30 AWG

Pin

Signal Name

Pin Description

Pin

Signal Name

Pin Description

1

I1+

CH0/CH1 current excitation source

27

I4–

CH6/CH7 current excitation return

2

NC

No connection

28

GND

Ground

3

C0H

CH0 sensor input (+)

29

C7L

CH7 sensor input (–)

5

4W01

CH0/CH1 4-wire, 2 sensor common

31

IC67

CH6/CH7 2 sensor common

6

IC01

CH0/CH1 2-sensor common

32

4W67

CH6/CH7 4-wire, 2 sensor common

7

C1H

CH1 sensor input (+)

33

C6L

CH6 sensor input (–)

8

C1L

CH1 sensor input (–)

34

C6H

CH6 sensor input (+)

9

GND

Ground

35

NC

No connection

10

I1–

CH0/CH1 current excitation return

36

I4+

CH6/CH7 current excitation source

12

NC

No connection

38

GND

Ground

14

C2L

CH2 sensor input (–)

40

C5H

CH5 sensor input (+)

15

4W23

CH2/CH3 4-wire, 2 sensor common

41

IC45

CH4/CH5 2 sensor common

16

IC23

CH2/CH3 2 sensor common

42

4W45

CH4/CH5 4-wire, 2 sensor common

17

C3H

CH3 sensor input (+)

43

C4L

CH4 sensor input (–)

18

C3L

CH3 sensor input (–)

44

C4H

CH4 sensor input (+)

19

GND

Ground

45

NC

No connection

20

I2–

CH2/CH3 current excitation return

46

I3+

CH4/CH5 current excitation source

21

+5V

Power output

47

+5V

Power output

23

DIO0

DIO channel 0

49

DIO7

DIO channel 7

25

DIO2

DIO channel 2

51

DIO5

DIO channel 5

26

DIO3

DIO channel 3

52

DIO4

DIO channel 4

Environmental

Table 20. Environmental speci ficat ion s

Parameter Specification

Mechanical

Table 21. Mechanical specifications

Parameter Specification

User connection len gt h 3 m (9.84 ft) max

Screw terminal conne c t or

Table 22. Screw terminal connector specifications

Connector type Screw terminal

Table 23. Screw terminal pinout

4 C0L CH0 sensor input (–) 30 C7H CH7 sensor input (+)

CJC sensor

11 I2+ CH2/CH3 current excitation source 37 I3– CH4/CH5 current excitation return

13 C2H CH2 sensor input (+) 39 C5L CH5 sensor input (–)

CJC sensor

22 GND Ground 48 GND Ground

24 DIO1 DIO channel 1 50 DIO6 DIO channel 6

30

Declaration of Conformity

Manufacturer: Measurement Computing Corporation
Address: 10 Commer ce Way
Suite 1008
Norton, MA 02766
USA
Category: Electrical equipment for measurement, control and laboratory use.

Measurement Computing Corporation declares under sole responsibility that the product

USB-5203

to which this declaration relates is in co nformity with the relevant provisions of t he following standards or other
documents:

EC EMC Directive 2004/108/EC: Electromagnetic Compatibility, EN 61326-1:2006, (IEC 61326-1:2005)
Emissions:

 EN 55011 (1990)/CISPR 11 Radiated emissions: Group 1, Class A
 EN 55011 (1990)/CISPR 11 Co nducted emissions: Group 1, Class A

Immunity: EN61326-1:2006, (IEC 61326-1:2005) Table 3 Immunity requirements for equipment used in
controlled EM environments.

 IEC 61000-4-2 (2001): Electrostatic Discharge immunity.
 IEC 61000-4-3 (2002): Radiated Electromagnetic Field immunity.

To maintain the safety, emission, and immunity standards of this declaration, the following conditions must be
met.

 The host computer, peripheral equipment, power sources, and expansion hardware must be CE compliant.
 Equipment must be operated in a controlled electromagnetic environment as defined by Standards EN

61326-1:2006, or IEC 61326-1:2005.

 Shielded wires must be used for all I/Os and must be less than 3 meters (9.75 feet) in length.
 The host computer must be properly grounded.
 The host computer must be USB 2.0 compliant.
 A protective ESD wrist strap should be used when connecting or disconnecting leads from screw terminal

blocks.

Note: Data acquisition equipment may exhibit noise or increased offsets when exposed to high RF fields
(>1V/m) or transients.

Declaration of Conformity based on tests conducted by Chomerics Test Services, Woburn, MA 01801, USA in
February, 2006. Test records are outlined in Chomerics Test Report #EMI4445.06. Further testing was
conducted by Chomerics Test Services, Woburn, MA. 01801, USA in November, 2008. Test records are
outlined in Chomerics Test report #EMI5193.08.

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

[phone]

Fax: [phone]

E-mail: [e-mail]

www.mccdaq.com