Specifications

1-5

In this example, the third line indicates the location of the ComputerBoards

PCI-DIO48 board. This is known since the ComputerBoards Vendor ID is

0x1307 and the Device ID is 0xb. In this case, you now can see that the

ComputerBoards board is plugged into the PCI slot 11 (Device No.), and that

this value must be entered in the dialog box entry in your I/O device driver for

each model that uses this I/O device.

xPC Target I/O Driver Structures

Properties for xPC Target I/O drivers are usually defined using the Parameter

dialog box associated with each Simulink block. However, for more advanced

drivers, the available fields defined by text boxes, check boxes,and pull down

lists are inadequate to define the behavior of the driver. In such cases, a more

textual description is needed to indicate what the driver has to do at runtime.

Texual in this context refers to a programming language like syntax and style.

xPC Target currently uses a textual description contained in message

structures for the RS232, GPIB, CAN (initialization) and the general counter

drivers (AMD9513).

What is a message structure? — A message structure is a MATLAB array

with each cell containing one complete message (command). A message

consists of one or more statements.

Syntax of a message statement — and each statement in a message has the

following format.

Structure_name(index).field_name = <field string or value>

The field names are defined by the driver, and need to be entered with the

correct upper and lower case letters. However, you can choose your own

structure name, and enter that name into the driver Parameter dialog box.

Message structure

First message Second message

Message(1).field

Third message