Acquire Temperature Data From a Thermocouple

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This example shows how to read data from NI devices that support thermocouple measurements.

Discover Devices That Support Thermocouples

To discover a device that supports thermocouple measurements, access the device in the table returned by thedaqlistcommand. This example uses an NI 9213 device. This is a 16 channel thermocouple module and is module 6 in the chassis.

d = daqlist("ni")

d = 12×4 table DeviceID Description Model DeviceInfo ___________ __________________________________ _____________ ____________________ "cDAQ1Mod1" "National Instruments NI 9205" "NI 9205" [1×1 daq.DeviceInfo] "cDAQ1Mod2" "National Instruments NI 9263" "NI 9263" [1×1 daq.DeviceInfo] "cDAQ1Mod3" "National Instruments NI 9234" "NI 9234" [1×1 daq.DeviceInfo] "cDAQ1Mod4" "National Instruments NI 9201" "NI 9201" [1×1 daq.DeviceInfo] "cDAQ1Mod5" "National Instruments NI 9402" "NI 9402" [1×1 daq.DeviceInfo] "cDAQ1Mod6" "National Instruments NI 9213" "NI 9213" [1×1 daq.DeviceInfo] "cDAQ1Mod7" "National Instruments NI 9219" "NI 9219" [1×1 daq.DeviceInfo] "cDAQ1Mod8" "National Instruments NI 9265" "NI 9265" [1×1 daq.DeviceInfo] "Dev1" "National Instruments PCIe-6363" "PCIe-6363" [1×1 daq.DeviceInfo] "Dev2" "National Instruments NI ELVIS II" "NI ELVIS II" [1×1 daq.DeviceInfo] "Dev3" "National Instruments PCIe-6363" "PCIe-6363" [1×1 daq.DeviceInfo] "Dev4" "National Instruments PCIe-6363" "PCIe-6363" [1×1 daq.DeviceInfo]

deviceInfo = d{6,"DeviceInfo"}

deviceInfo = ni: National Instruments NI 9213 (Device ID: 'cDAQ1Mod6') Analog input supports: -0.078 to +0.078 Volts range Rates from 0.1 to 1351.4 scans/sec 16 channels ('ai0' - 'ai15') 'Voltage','Thermocouple' measurement types This module is in slot 6 of the 'cDAQ-9178' chassis with the name 'cDAQ1'.

Add a Thermocouple Channel

Create a DataAcquisition, change its scanRateto four scans per second, and add an analog input channel withThermocouplemeasurement type.

dq = daq("ni"); dq.Rate = 4; ch = addinput(dq,"cDAQ1Mod6","ai0","Thermocouple");

Configure Channel Properties

Set the thermocouple type to K and units to Kelvin (the thermocouple type should match the sensor configuration).

ch.ThermocoupleType ='K'; ch.Units ='Kelvin'; ch

ch = Index Type Device Channel Measurement Type Range Name _____ ____ ___________ _______ ________________ _____________________ _______________ 1 "ai" "cDAQ1Mod6" "ai0" "Voltage (Diff)" "+73 to +1523 Kelvin" "cDAQ1Mod6_ai0"

Acquire and Plot Data

Use thereadcommand to acquire data.

data = read(dq, seconds(1)); plot(data.Time, data.cDAQ1Mod6_ai0); ylabel('Temperature (K)');