General Standards 24DSI12 Analog Input

General Standards 24DSI12 Analog Input


Simulink® Real-Time™ Library for General Standards

Scaling Output to Input

I/O Module Input

Block Output Data Type






Block Parameters

Channel vector

This is a vector of channels. Specifies the output channels that the block works on. Each channel can appear only once in this vector. For example, to use the first, third, and fifth analog input channels, enter:

Input range

From the list, select an input range code for all A/D channels. This driver does not allow the selection of a different range for individual channels.

The following table is a list of the ranges for this driver and the corresponding range codes.

Input Range (V)

Range Code

-10 to +10


-5 to +5


-2.5 to +2.5


Frame Size, Sample Rate, and Sampletime

These three parameters are not independent but are related by:

FrameSize = Sampletime × SampleRate.

After you specify two of the parameters, the equation determines the third parameter. Enter -1 to have the block calculate that value from the other values.

For example, if you set Frame Size to 64 and Sample Rate to 44100, specify Sampletime as -1. It is computed internally to 0.001451247165533 seconds. This example model executes every 0.001451247165533 seconds, which is every 64 samples at 44 kHz.

Frame size (samples)

Enter the number of samples in one frame for each channel listed in Channel vector. An interrupt occurs on the board each time the board acquires this number of samples.

Sample rate

Enter the frequency at which the samples are taken, in Hz. This frequency must be in the range 2000 to 200000 Hz (2 kHz to 200 kHz).

Sample time (Frame completion time)

Enter the time between frame completions.

Output format

From the list, select one of the following. The output value is of type double.

+- Input Range (+-10 +-5 or +-2.5)

Specifies that the value is scaled to the input voltage range.

signed 32 bit integer [-2^23 2^23-1]

Specifies that the value is a direct 24-bit value converted to a floating integer.


From the list, select one of the following analog input filters:

  • Low Frequency

  • High Frequency

This parameter takes effect only if the Sample rate parameter exceeds 100 kHz. See the manufacturer documentation for more information.

Triggering mode

From the list, select one of the following:

Hardware clock/Initiator

Select this value if the board is the timing master.


Select this value if the board is connected to another board that is the timing master.

Autocal at download

Select this check box to execute the autocalibration cycle as part of the initial setup when the model is downloaded to the target computer. You might autocalibrate, for example, after setting the acquisition frequency. You can consider clearing this check box if you do not need to worry about exact voltage levels.

    Note:   The autocalibration cycle requires approximately 5 seconds to complete. Refer to the manufacturer documentation for further information on autocalibration.

External sync signal type

From the list, select one of the following to select a signal type for the clock output signal that can be connected to other input boards or to the PMC66-16AO16 output board.


Low voltage differential signaling. Select this value for greater reliability, especially when using the General Standards twisted-pair ribbon cables.


See the manufacturer documentation for guidelines on using this signal type.

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')

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