Controller Circuit

For a better understanding of how to specify device settings when using both analog and digital signals, this section uses the I/O board DAS-1601 from Keithley-Metrabyte as an example. The following is a specification summary of the DAS-1601 board:

•  Analog input (A/D) -- 16 single-ended or 8 differential analog inputs (12-bit), polarity is switch configured as either unipolar (0 to 10 volts) or bipolar(+/- 10 volts). Gain is software configured to 1, 10, 100, and 500. 
• Digital input -- Four unidirectional digital inputs Analog output (D/A) -- Two
•  analog outputs (12-bit). Gain is switch configured as 0 to 5 volts, 0 to 10 volts, +/- 5 volts, or +/- 10 volts 
• Digital output -- Four unidirectional digital outputs 
• Base address -- Switch configured base address 

This section explores different configurations for input signals. Once an Analog Input block has been placed in the model and the I/O board selected and configured, you can set up the Analog Input block to handle input signals. Single analog input -- The most basic case is for a single analog input signal that will be physically connected to the first analog input channel on the board. In the Block Parameter: Analog Input dialog box, and the Input channels box, enter 1 or [1]

The use of brackets is optional for a single input. Input vector with differential analog -- Analog channels are numbered starting with channel 1 and continue until you reach a number corresponding to the maximum number of analog signals supported by the I/O board. In the case of the DAS-1601, when configured as differential inputs, eight analog channels are supported. The analog input lines are numbered 1 through 8. The complete input vector is

[1 2 3 4 5 6 7 8] or [1:8]

If you wanted to use the first four differential analog channels, enter
 [1 2 3 4]
Input vector with single-ended analog -- Now, assume your DAS-1601 board is configured to be single-ended analog input. In this case, 16 analog input channels are supported. The complete input vector is
 [1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16] or [1:16]
To use the first four single-ended analog input channels, enter
 [1 2 3 4] or [1:4]