Documentation

Measurement Computing PCI-DAS-TC Thermocouple

PCI-DAS-TC Thermocouple

Library

Simulink® Real-Time™ Library for Measurement Computing™

Scaling Input to Output

I/O Module Input

Block Input Data Type

Scaling

Volts

Double

temperature in either degrees C, K, or F.

Block Parameters

Conversion rate (interrogation time)

From the list, choose either 50Hz, 60Hz, or 400 Hz. This is the conversion rate for the V-F A/D converter. The conversion rate is the same for all input channels.

Number of samples for moving average

From the list, choose a value from 1 to 16. Converted signal values are put into a cyclic buffer of size N which is used to calculate the moving average over these N samples.

Number of channels to be acquired (1..n)

From the list, choose a value from 1 to 16. This is the number of input channels activated for conversion. The first channel of the scan is an input channel with the number 1 and the last channel has the number N.

Vector input thermocouple types (cell array of char)

For each acquired channel, enter a valid type of either 'J', 'K', 'E', 'T', 'R', 'S', or 'B'. This vector defines the type of thermocouple for each channel. The vector must be the same length as the Number of channels to be acquired.

Vector of input gains (double array)

For each acquired channel, enter a valid input gain of either 1, 125, 166.7, or 400. This vector defines the input gain for each channel. The vector must be the same length as the Number of channels to be acquired.

Vector or temperature formats (cell array of char)

For each acquired channel, enter a valid format of either 'C' or 'F'. 'C'= Celsius and 'F'= Fahrenheit. The vector must be the same length as the Number of channels to be acquired.

Read and output CJC temperature

If you want the block to read, convert, and output the temperature of the cold junction (CJC) sensor on the board, select this check box. If selected, the block shows an additional output port with the value of the CJC temperature.

Sample time

Enter the base sample time or a multiple of the base sample time (-1 means sample time is inherited).

PCI slot (-1:autosearch)

If only one board of this type is in the target computer, enter -1 to locate the board.

If two or more boards of this type are in the target computer, enter the bus number and the PCI slot number of the board associated with this driver block. Use the format [BusNumber,SlotNumber].

To determine the bus number and the PCI slot number, type:

tg = slrt;
getPCIInfo(tg, 'installed')

Each time a real-time application containing this driver block is downloaded to the target computer, the board automatically does a full calibration. Thermocouple sensor calibration is an extensive procedure and because it has to take place for each channel independently, the calibration time can easily exceed several seconds, especially when the number of channels to be acquired is 5 or higher. Because of this long calibration period during the initialization stage of the real-time application, the download procedure can time out and return an error message. To avoid this error, increase the default timeout duration. See Increase the Time for Downloads.

External Websites

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