National Instruments SCC-TC Series Thermocouple Input Modules User's Manual
Contents
1. SCC TC Series Thermocouple Input Modules User Guide 18 ni com Table 1 SCC Module Pin Signal Connections for SCC TCOX Modules Continued Pin Number Signal 13 15 V 14 15 V 15 16 17 18 19 20 National Instruments Corporation 19 SCC TC Series Thermocouple Input Modules User Guide National Instruments NI ni com and NI DAQ are trademarks of National Instruments Corporation Product and company names mentioned herein are trademarks or trade names of their respective companies For patents covering National Instruments products refer to the appropriate location Help Patents in your software the patents txt file on your CD orni com patents P y p y R 323099B 01 Sep03 2002 2003 National Instruments Corp All rights reserved2. 1 24 0 to 100 2 0 82 100 to1 600 1 75 0 4 S 50 to 0 3 1 3 0 to 1 400 2 1 1 400 to 1 600 2 5 1 T 200 to 100 2 5 2 100 to 400 1 0 9 Cold Junction Sensor Cold junction sensor accuracy 0 4 C max from 15 to 35 C 0 75 C max from 0 to 15 C and 35 to 55 C OU NUL ANNE D R E E E E 1 91 V 0 C to 0 58 V 55 C Ss Note The accuracy specification includes the combined effects of the temperature sensor accuracy and the temperature difference between the temperature sensor and any thermocouple connector The temperature sensor accuracy includes component tolerances temperature drifts and self heating effects It does not include measurement device errors Open Thermocouple Detection Pull up resistor eee eeeeeeeeeeeees 10 MQ Bias eSiStOL eee eee eeeeseeeeeeeteeeeees 10 MQ Maximum field wire gauge 16 AWG Power Requirement Analog POWED eceeeeseeseeeeseteeeeeeees 60 mW max FIS YV ses echasctscesiedatagedeadestepatesecviapstets 2 mA max HDS Vanner 2 mA max Digital power 5 V 0 cee eeeeeeeeeeees 0 0 mW National Instruments Corporation 15 SCC TC Series Thermocouple Input Modules User Guide Physical TCOL dimensions 0 eee eee eeeeeeeee 7 8 cm by 2 92 cm by 1 85 cm 3 1 in by 1 15 in by 0 73 in TCO2 dimensions eee eee eects 8 89 cm by 2 92 cm by 1 85 cm 3 50 in by 1 15 in by 0 73 in IOs ean a a R ae eeh One 20 pin right angle male conn
3. 7K 25V L LN oa T OTHE 1 gt gt gt i ACH X8 p Z5ko t10pFt o4uF T eee one n EOT 2 5 kQ V Hi Figure 3 SCC TCOX Signal Connections Cold Junction Sensor Output and Accuracy The cold junction sensor voltage output varies from 1 91 to 0 58 V over a 0 to 55 C temperature range ny Note NI DAQ includes thermistor conversion utilities that implement the equations listed below Refer to your software documentation for more information on these utilities SCC TC Series Thermocouple Input Modules User Guide 6 ni com You can use the following formulas to convert the cold junction sensor voltage to cold junction temperature T C Tg 273 15 where Tx is the temperature in kelvin 1 Ty E a b InR c nR J where a 1 295361 x 103 b 2 343159 x 104 c 1 018703 x 107 Rris the resistance of the thermistor in ohms 4 R 5 o00 TEMPOUT J j 2 5 Vreupou where Vrempout is the output voltage of the cold junction sensor T F PEO 19 45 5 where T F and T C are the temperature readings in degrees Fahrenheit and Celsius respectively 3 Note Vrgmpour varies from 1 91 V at 0 C to 0 58 V at 55 C For best resolution use the maximum gain for this range on the analog input channel For the cold junction sensor measurement accuracy refer to the Specifications section Uncompensated Connectors and Accuracy If you are using an SCC TCO02 with an uncompe
4. CIT OF Seen heck Astacio 0 08 max Gain Stability ee ceeeesseeesteeeeeesecenees 0 0005 C max Offset CLT OF ensimmainen aA 5 uV max post calibration Offset stability cccccescsescecessssteeeeesees 0 6 uV C max Nonlinearity 0 0 ccccceseescsseeseseseeeceeseees 0 004 max Recommended warm up time 5 minutes Measurement Accuracy Thermocouple Temperature Maximum Typical Type Range C Inaccuracy C Inaccuracy C B 400 to 600 2 5 0 31 600 to 1 800 2 0 13 E 200 to 100 2 1 76 100 to 600 1 1 600 to 1 000 1 5 0 6 J 200 to 100 2 1 6 100 to 500 1 0 9 500 to 1 100 1 5 0 72 Temperature range is 23 C 5 C N Temperature range is 0 to 50 C w Total system measurement error for operating temperature within 5 C of calibration temperature Includes PCI AT MIO 16XE 50 one year accuracy specification of 0 01 412 uV SCC TC01 02 accuracy specification of 0 08 5 uV and reference junction measurement accuracy of 0 5 C Assumes averaging Non averaged single point reading has an additional uncertainty up to 0 1 C for J type thermocouple SCC TC Series Thermocouple Input Modules User Guide 14 ni com Thermocouple Temperature Maximum Typical Type Range C Inaccuracy C Inaccuracy C K 200 to 100 2 5 1 25 100 to 600 1 25 0 67 600 to 1 200 2 0 45 N 200 to 100 2 5 2 100 to 1 300 2 0 7 R 50 to 0 3
5. GND TC is the positive thermocouple lead and TC is the negative thermocouple lead The GND terminal connects to AIGND on the E Series DAQ device The SCC TCOX has a 10 MQ bias resistor connected from the negative thermocouple input to ground This resistor allows the thermocouple to be ground referenced or floating without requiring external bias resistors connected to ground For ANSI color coded J type thermocouples the red wire is negative and the white wire is positive Refer to the thermocouple data sheet if possible You can find information about other color coding schemes in the NI KnowledgeBase at ni com support National Instruments Corporation 5 SCC TC Series Thermocouple Input Modules User Guide The amplified thermocouple signal and cold junction sensor signal are measured by E Series DAQ device channel X and channel X 8 respectively where X is 0 to 7 depending on where you plug the SCC TCOX Refer to Figure 3 for SCC TCOX signal connections E Series AL See A aCe Oe Nee ONE ee OEE DAQ Device _ A Ref 5V Li Thermocouple 10 MQ l Source 10 kQ ha Pe bk 2 Pole Filter TC i Pole Filter ii Jd ACH X i lt 1 10 kQ Buffer Stage ii CHO i VWV T TC i 5 L i ffset Li i 3 TOMA Calibrator a GND i SCC TC02 YV i only Ls A Ref Sv gt i i AISENSE oe gt AIGND i 5 kQ 7 LM 4040 0 1 a
6. compensation voltage by converting the cold junction temperature you got in step 2 to a thermocouple voltage Use the polynomial expressions applicable to the type of thermocouple you are using Apply the cold junction compensation to the thermocouple reading by adding the cold junction compensation voltage you got in step 3 to Vrce Calculate the thermocouple temperature by converting the voltage result you got in step 4 to a temperature Use the polynomial expressions applicable to the type of thermocouple you are using This calculation gives you a linearized temperature measurement 3 Note Polynomials come from NIST Monograph 175 Specifications These specifications are typical at 25 C unless otherwise stated Analog Input Number of input channels e 1 DIFF Input signals ce eeeeeeseeeseeeeeeeeneeeeeers Thermocouples of types B E J K N R S and T Input signal range 100 mV Input impedance eee eeeeeeeeeees 10 MQ powered on 10 kQ powered off or overload Bandwidth ccccccccecseseeseeseserereeees 2 Hz National Instruments Corporation 13 SCC TC Series Thermocouple Input Modules User Guide Amplifier Characteristics Open thermocouple detection current 250 nA max assuming floating thermocouple Common mode rejection ratio 110 dB min OUutpUt FANE creea 10 V max Transfer Characteristics GAIN 3 oe eee ee ieee eee 100 Gal
7. requires a 7 to 42 VDC power supply not included One or more SCC TCOX modules SCC TC Series Thermocouple Input Modules User Guide Read Me First Safety and Radio Frequency Interference SC 2345 User Manual available online at ni com SC 2345 Quick Reference Label 68 pin E Series DAQ device documentation and 68 pin cable Oovovovowo oO 1 8 in flathead screwdriver SCC TC Series Thermocouple Input Modules User Guide 2 ni com Q Numbers 1 and 2 Phillips screwdrivers Q Wire insulation strippers Q NI DAQ current version for Windows 2000 NT XP i Note Software scaling of measurements is not supported on the Macintosh operating system Refer to the Converting Voltage Measurements to Temperature Measurements section for more information about measurement scaling Unpacking the Module SCC modules are shipped in antistatic envelopes to prevent electrostatic damage ESD to the modules ESD can damage several components on these products UN Caution Never touch the exposed pins of connectors To avoid damage from ESD when you handle the module take the following precautions e Ground yourself by using a grounding strap or by touching a grounded object e Touch the antistatic envelope to a metal part of the computer chassis before removing the module from the envelope Remove the module from the envelope and inspect the module for loose components or any sign of damage Notify NI if the module appears damaged i
8. the thermocouple which corresponds to an error of 0 09 C With 10 MQ pull up and bias resistors a common mode voltage of 2 5 VDC develops if the thermocouple is floating The common mode rejection of the SCC TCOX is sufficiently high which results in the offset voltage being negligible in most applications If your application demands extremely high accuracy you can eliminate these errors by calibrating the system Refer to the Calibrating System Offsets section for more information Configuring the SCC System Measurement amp Automation Explorer MAX Configuration Run MAX to configure the SCC system Complete one of the following procedures depending on the version of NI DAQ used in your application SCC TC Series Thermocouple Input Modules User Guide 8 ni com NI DAQmx Complete the following steps to configure the SCC TC module using NI DAQmx 1 Open Measurement amp Automation Explorer 2 Right click Devices and Interfaces and select Create New 3 Under NI DAQmx SCC Connector Block select SC 2345 Click Finish 4 Inthe SCC Connector Block Configuration window configure the SCC system as follows a Specify the SCC Carrier Type The location of the SCC sockets change depending on the SCC carrier type b Select the DAQ Device that is connected to the SC 2345 c Enter the SCC Connector Block ID The default value is SCC1 d In the J21 drop down list next to Power select the correct SC 2345 power co
9. A USER GUIDE SCC TC Series Thermocouple Input Modules The SCC TC Series thermocouple input modules SCC TC01 and SCC TC02 accept input signals from B E J K N R S and T type thermocouples The thermocouple inputs are filtered and passed into a differential amplifier with a gain of 100 The output of the amplifier passes through a dual pole 2 Hz filter Each module contains thermistor circuitry powered by a 2 5 V reference to compensate for cold junction effects Each module also can detect open thermocouple circuits Alternatively you can connect voltage signals up to 100 mV to the screw terminals of the SCC TCO2 and use it as a low bandwidth millivolt input module Conventions The following conventions are used in this guide lt gt Angle brackets that contain numbers separated by an ellipsis represent a range of values associated with a bit or signal name for example ai lt 0 7 gt The symbol leads you through nested menu items and dialog box options to a final action The sequence File Page Setup Options directs you to pull down the File menu select the Page Setup item and select Options from the last dialog box This icon denotes a note which alerts you to important information gt g This icon denotes a caution which advises you of precautions to take to avoid injury data loss or a system crash When this symbol is marked on the product refer to the Read Me First Safety and Radio F
10. e available for digital input output DIO conditioning or control Refer to the SC 2345 User Manual for more information on configuring connecting and installing SCC modules Sy Note SCC TCOX dual stage configuration is only available in NI DAQ 7 1 or later Connecting the Input Signals The SCC TCO1 has a two prong uncompensated thermocouple miniconnector that accepts any miniature or subminiature two prong male thermocouple connector The SCC TC02 has a three position screw terminal connector that accepts 28 to 16 AWG thermocouple wires The screw terminal connector provides a ground connection for shielded thermocouples Otherwise the two modules function identically To use an SCC TCO1 plug the male thermocouple connector into the module SCC TC Series Thermocouple Input Modules User Guide 4 ni com The SCC TC02 has a fixed screw terminal receptacle and a removable screw terminal block as shown in Figure 2 1 SCC Screw Terminal Receptacle 2 Removable Screw Terminal Block Figure 2 SCC TCO2 Two Part Screw Terminal System After you install the SCC TCO02 attach the input signals to the screw terminals of the module 1 Remove power from the signal lines 2 Strip 7 mm 0 28 in of insulation from the ends of the signal wires 3 Insert the wires into the screw terminals 4 Tighten the screws to 0 5 to 0 6 N m 4 4 to 5 3 Ib in of torque The SCC TC02 accepts up to three signals TC TC and
11. easurement as described in the Converting Voltage Measurements to Temperature Measurements section 6 Adjust the potentiometer on the top of the SCC TCOX so that the measured temperature is equal to the calibration temperature Converting Voltage Measurements to Temperature Measurements 3 Note NI DAQ includes thermocouple and thermistor conversion utilities that implement the conversions required in steps 3 and 5 of the following procedure Refer to your software documentation for more information on these utilities Your software environment may return only voltage measurements from E Series DAQ devices If so you must convert voltage measurements to temperature measurements To make this conversion complete the following steps 1 Measure the thermocouple voltage a Read the thermocouple channel on the E Series DAQ device Veseries CH X b Calculate the thermocouple voltage by using the following formula y V ESERIES ue 100 SCC TC Series Thermocouple Input Modules User Guide 12 ni com where Vrc is thermocouple voltage Veseries 18 E Series DAQ device voltage This step provides proper scaling for the thermocouple amplifier in the SCC TCOX Measure the reference junction cold junction temperature a Read the thermistor voltage ACH X 8 b Convert the thermistor voltage to cold junction temperature using the formula in the Cold Junction Sensor Output and Accuracy section Calculate the cold junction
12. ector 3 pin screw terminal system SCC TC02 two prong mini connector SCC TC01 Screw terminal field wiring gauge SCC TC02 eeeseeseeserirsessrersce 28 to 16 AWG Maximum Working Voltage Environmental Safety Maximum working voltage refers to the signal voltage plus the common mode voltage Each input must remain within 12 V of chassis ground Installation Category I Operating temperature 0 ee 0 to 50 C Storage temperature ee eee 20 to 70 C Humidity ssassn 10 to 90 RH noncondensing Maximum altitude 2 000 m Pollution Degree indoor use only 2 The SCC TCOX meets the requirements of the following standards for safety and electrical equipment for measurement control and laboratory use e TEC 61010 1 EN 61010 1 e UL3111 1 UL 61010B 1 e CAN CSA C22 2 No 1010 1 SCC TC Series Thermocouple Input Modules User Guide 16 ni com 3 Note For UL and other safety certifications refer to the product label or visit ni com hardref nsf search by model number or product line and click the appropriate link in the Certification column Electromagnetic Compatibility 3 Electrical emissions EN 55011 Class A at 10 m FCC Part 15A above 1 GHz Electrical iMMUNILY ee eee eeeeeeeee Evaluated to EN 61326 1997 A2 2001 Table 1 CE C Tick and FCC Part 15 Class A Compliant Note For full EMC compliance you must operate this device with shielded cabling In addition all cover
13. fy information about the E Series DAQ device being used and the CJC source and click Finish To test the channel click Test You have finished configuring the Traditional NI DAQ virtual channel Calibrating System Offsets To calibrate the offset voltage of the SCC TCOX in the system using the E Series DAQ device complete the following steps The E Series DAQ device must be on for 30 minutes before you calibrate the offset voltage 1 2 3 National Instruments Corporation Select the desired channel and gain on the E Series DAQ device Short the inputs on the SCC TCOX screw terminals or miniplug While acquiring data on the selected channel use a screwdriver to adjust the potentiometer protruding through the top of the module until you read 0 VDC 11 SCC TC Series Thermocouple Input Modules User Guide Calibrating the SCC TCOX Using a Thermocouple Calibrator To calibrate the system using a thermocouple calibrator complete the following steps 1 Make sure that the thermocouple connections at both the SCC and the thermocouple calibrator are at the same temperature 2 Connect the thermocouple calibrator to the SCC TCOX For best results use thermocouple wire of the same length and type that you use in the thermocouple 3 Set the thermocouple calibrator to the required calibration temperature 4 Measure the calibrator voltage using the SCC TCOX 5 Convert the measured calibrator voltage to a temperature m
14. n any way Do not install a damaged module Store the module in the antistatic envelope when it is not in use Installing the Module UN Caution Refer to the Read Me First Safety and Radio Frequency Interference document before removing equipment covers or connecting disconnecting any signal wires National Instruments Corporation 3 SCC TC Series Thermocouple Input Modules User Guide A blue stripe on the label identifies the SCC TCOX as an analog input module The label also displays the icon shown in Figure 1 TC Figure 1 SCC TCOX Icon You can plug the SCC TCOX into any analog input socket on the SC 2345 The socket you select determines which E Series DAQ device channels receive the SCC TCOX signals For single stage input conditioning plug the SCC TCOX into any socket J X 1 where X is 0 to 7 and connect the input signals to the module as described in the Connecting the Input Signals section If you use the SCC TCOX in a dual stage configuration the SCC TCOX must be the first stage module Plug it into any socket J X 9 and plug the second stage SCC into socket J X 1 where X is 0 to 7 Connect the input signals to SCC TCOX as described in the Connecting the Input Signals section The SC 2345 connects the output signals of the first stage SCC to the inputs of the second stage SCC An example of dual stage conditioning in an SCC TCOX followed by an SCC LPO1 lowpass filter module Sockets J9 to J16 also ar
15. nfiguration Refer to the SC 2345 User Manual for information on power configurations e For each SCC module physically installed in the SC 2345 add a corresponding entry in the SC 2345 configuration window To add the SCC click the socket drop down list and select the correct module If the module name does not appear in the list either the module is not allowed in that location or you do not have the current version of NI DAQ If you do not have the current version of NI DAQ download it from ni com f Click OK after completing all SCC entries to complete the configuration process 5 Close MAX 3 Note Configuring the SCC system using MAX automatically sets the E Series DAQ device analog input mode to nonreferenced single ended NRSE Traditional NI DAQ Complete the following steps to configure the SCC TC module using Traditional NI DAQ ain a Sad National Instruments Corporation Open Measurement amp Automation Explorer Expand Devices and Interfaces Expand Traditional NI DAQ Devices Right click the E Series DAQ device connected to the SC 2345 and select Properties Select the Accessory tab 9 SCC TC Series Thermocouple Input Modules User Guide 10 11 12 13 Under Accessory select SC 2345 Click the Configure button A new window appears listing the sockets connector reference designators of the SC 2345 Select the SC 2345 socket where you installed an SCC Click Add and select the SCC
16. nsated SCC panelette temperature gradients between the module and the junctions on the panelette affect the accuracy of your measurements National Instruments Corporation 7 SCC TC Series Thermocouple Input Modules User Guide Detecting Open Thermocouples The SCC TCOX contains a 10 MQ pull up resistor that connects to 5 V to detect open thermocouples To determine if you have an open thermocouple check whether the corresponding E Series DAQ device channel is saturated The pull up and bias resistors saturate the channel by applying 2 5 V at the input of an open channel This results in saturation to either the positive or negative rails of the E Series DAQ device 10 V Errors Due to Open Thermocouple Detection Circuitry The open thermocouple detection circuitry can cause measurement errors These errors are the results of common mode voltage at the input of the SCC and current leakage into the signal leads The 10 MQ bias resistor in the SCC TCOX causes this error to be negligible With the 10 MQ bias resistor connected to ground and the 10 MQ pull up resistor connected to 5 VDC a current leakage of approximately 0 25 WA 5 V 20 MQ flows into the unbroken floating thermocouple Long thermocouple leads result in larger voltage drops due to lead resistance For example if you have a 24 AWG J type thermocouple that is 20 ft long a voltage drop of approximately 4 uV 0 145 O ft 0 658 Q ft x 20 ft x 0 25 UA can develop in
17. requency Interference document shipped with the product for precautions to take Qr NATIONAL p INSTRUMENTS AX A bold italic monospace SC 2345 SCC When symbol is marked on a product it denotes a warning advising you to take precautions to avoid electrical shock When symbol is marked on a product it denotes a component that may be hot Touching this component may result in bodily injury Bold text denotes items that you must select in the software such as menu items and dialog box options Bold text also denotes parameter names Italic text denotes variables emphasis a cross reference or an introduction to a key concept This font also denotes text that is a placeholder for a word or value that you must supply Text in this font denotes text or characters that you should enter from the keyboard sections of code programming examples and syntax examples This font is also used for the proper names of disk drives paths directories programs subprograms subroutines device names functions operations variables filenames and extensions and code excerpts SC 2345 refers to both the SC 2345 connector block and the SC 2345 configurable connector SCC refers to any SCC series signal conditioning module What You Need to Get Started To set up and use the SCC TCOX you need the following items Q SC 2345 with one of the following SCC PWRO1 SCC PWRO2 and the PSO1 power supply SCC PWRO3
18. s and filler panels must be installed CE Compliance The SCC TCOX meets the essential requirements of applicable European Directives as amended for CE marking as follows Low Voltage Directive safety 73 23 EEC Electromagnetic Compatibility Directive EMC eee eeeeeeeeeneeeees 89 336 EEC Note Refer to the Declaration of Conformity DoC for this product for any additional regulatory compliance information To obtain the DoC for this product visit ni com hardref nsf search by model number or product line and click the appropriate link in the Certification column National Instruments Corporation 17 SCC TC Series Thermocouple Input Modules User Guide 1 0 Connector Pin Assignments Figure 4 shows the I O connector pins on the bottom of the module 60000000000 0000000000 Figure 4 SCC Module Bottom View Table 1 lists the signal connection corresponding to each pin ACH X and ACH X 8 are the analog input signal channels of the E Series DAQ device AIGND is the analog input ground signal and is the reference for ACH X and ACH X 8 AGND is the reference for the 15 V supplies and REF5V AIGND and AGND connect to the SC 2345 at the SCC PWR connector Table 1 SCC Module Pin Signal Connections for SCC TCOX Modules Pin Number Signal 1 ACH X 2 3 4 ACH X 8 5 6 AIGND 7 a 8 9 10 11 AGND 12 REF5V
19. ting a channel you can select only one channel Click Next Enter a name for the task or global channel and click Finish In the Channel List box select the channel s you want to configure You can select blocks of channels by pressing the lt Shift gt key while making the selections or select individual channels by pressing the lt Ctrl gt key while making the selections SCC TC Series Thermocouple Input Modules User Guide 10 ni com Enter the specific values for your application in the Settings tab Context help information for each setting is provided on the right side of the screen Choose the type of thermocouple you have connected to your SCC module For the CJC Source parameter select Built In Click Test to test the channel You should be able to view your measurement in the window that appears You have finished configuring the NI DAQmx task or global channel Creating a Virtual Channel in Traditional NI DAQ To create a Traditional NI DAQ virtual channel complete the following steps Gye D 8 Open Measurement amp Automation Explorer Right click Data Neighborhood and select Create New Select Traditional NI DAQ Virtual Channel and click Finish Click Next to select Analog Input as the type of channel to configure From the drop down list select the appropriate Thermocouple type and click Next Enter the rest of the values as they apply to your setup and click Next On the next screen speci
20. you installed If the module name does not appear in the list either the module is not allowed in that location or you do not have the current version of NI DAQ If you do not have the current version of NI DAQ download it from ni com If you make a selection mistake select the socket and click Remove Repeat steps 8 and 9 for each newly installed SCC Click OK after completing all SCC entries Click OK to complete the configuration process and close MAX nye Note Configuring the SCC system using MAX automatically sets the E Series DAQ device analog input mode to nonreferenced single ended NRSE Virtual Channels Physical Channels and Tasks After you have installed and configured your SCC hardware you can use software tools within MAX to further configure the module and take measurements Creating an NI DAQmx Task or Global Channel To create an NI DAQmx task or global channel complete the following steps 1 Open Measurement amp Automation Explorer 2 Right click Data Neighborhood and select Create New 3 Select NI DAQmx Task or NI DAQmx Global Channel and click Next 4 Select Analog Input then select Temperature and then select Thermocouple 5 Ifyou are creating a task select the channels to add to the task You can select blocks of channels by pressing the lt Shift gt key while making the selections or select individual channels by pressing the lt Ctrl gt key while making the selections If you are crea
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