获得温度数据an RTD

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This example shows how to acquire temperature data from a Resistive temperature device (RTD) and display the readings. The device is attached inside a PC case to monitor the internal temperature changes.

Discover Devices That Support RTDs

To discover a device that supports bridge sensor measurements, access the device in the table returned by thedaqlistcommand. This example uses an NI 9219 module in National Instruments® CompactDAQ Chassis NI cDAQ-9178. This is a 24-Bit Universal Analog Input module and is module 7 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{7,"DeviceInfo"}

deviceInfo = ni: National Instruments NI 9219 (Device ID: 'cDAQ1Mod7') Analog input supports: 9 ranges supported Rates from 0.1 to 100.0 scans/sec 4 channels ('ai0','ai1','ai2','ai3') 'Voltage','Current','Thermocouple','RTD','Bridge' measurement types This module is in slot 7 of the 'cDAQ-9178' chassis with the name 'cDAQ1'.

Add an RTD Channel

Create a DataAcquisition, and add an analog input channel withRTDmeasurement type.

dq =采集("ni"); dq.Rate = 30; ch = addinput(dq,"cDAQ1Mod7","ai3","RTD");

Set Sensor Properties

Refer to the sensor data sheet and match the values accordingly. In this example, an SA1-RTD series sensor from Omega® is used. Set units to"Fahrenheit", RTD type to"Pt3851", configure the RTD circuit as"FourWire", and set the resistance to 100 ohms.

ch.Units ="Fahrenheit"; ch.RTDType ="Pt3851"; ch.RTDConfiguration ="FourWire"; ch.R0 = 100;

Set ADCTimingMode

By default, the ADC timing modeADCTimingModeof the channel is set to"HighResolution". Set theADCTimingModeto"HighSpeed".

ch.ADCTimingMode ="HighSpeed";

Acquire and Plot Data

Use thereadcommand to acquire data.

data = read(dq, seconds(1)); plot(data.Time, data.cDAQ1Mod7_ai3); degreeSign = 176; ylabel(sprintf("Temperature (%cF)", degreeSign));