National Instruments PCI-6527 Digital Input

National Instruments PCI-6527 Digital Input block


Simulink® Real-Time™ Library for National Instruments®


The PCI-6527 has one chip with 3 ports (A,B,C) for digital input. Each port has a maximum of 8 digital I/O lines. Use a separate driver block for each port.

    Note:   The interrupt on change capability of this board is not used.

Scaling of Input to Output

I/O Module Input

Block Input Data Type




< 0.5 = 0
≥ 0.5 = 1

Block Parameters

Channel vector

Enter numbers between 1 and 8 to select the digital input lines used with this port. This driver allows the selection of individual digital input lines in arbitrary order. The number of elements defines the number of digital lines used.

For example, to use all of the digital inputs for one port, enter


Number the lines beginning with 1 even if this board manufacturer starts numbering the lines with 0.


From the list, choose either A, B, or C. The Port parameter defines which port is used for this driver block. Each port has a maximum of 8 digital inputs. In each case, one block is required for each port.

The documentation for this board from National Instruments labels these ports 0, 1, and 2.

Filter vector

This is a Boolean vector that selects which input lines to filter. For example, if you enter a Channel vector of [1,3,5], and you want to filter all three lines, enter


If you want to filter lines 1 and 5, but not line 3, then enter


If the filter vector is a single element, then it is scaler expanded to the same width as the Channel vector. In the example above, if the Filter vector is [0], it is expanded to [0,0,0]. Likewise, if the Filter vector is [1]it is expanded to [1,1,1].

Filter interval

Enter the time interval the filter uses to determine a stable pulse. If the input pule is shorter then this interval, it is ignored. The same filter interval applies to each filtered input, and if you filter on more than one digital input block for this board, you must enter the same Filter interval for each block.

A reasonable value for the Filter interval would be 200 to 300 us.

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')

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