xPC Target

I/O Driver Block Library

A driver block does not represent an entire board, but an I/O section supported by a board. Therefore, the xPC Target library can have more than one block for each physical board. I/O driver blocks are written as C-code S-functions (noninlined S-functions). The source code for the C-code S-functions with xPC Target is included.

xPC Target supports PCI and ISA buses. If the bus type is not indicated in the driver block number, you can determine the bus type of a driver block by checking the block's parameter dialog box. The last parameter is either a PCI slot, for PCI boards, or a base address, for ISA boards.

You can open the I/O device driver library with the MATLAB command xpclib. The library xpclib contains sublibraries grouped by the type of I/O function they provide.

When you double-click one of these groups, the sublibrary opens, displaying a list grouped by manufacturer as shown below.

Double-clicking one of the manufacturer groups then displays the set of I/O device driver blocks for the specified I/O functionality (for example, A/D, D/A, Digital Inputs, Digital Outputs, and so on).

The following figure shows the A/D drivers for the manufacturer ComputerBoards, Inc.

When you double-click one of these blocks, a Block Parameters dialog box opens, allowing you to make hardware-specific parameters. Parameters typically include

• Sample time
• Number of channels
• Voltage range
• Base address (ISA boards)

I/O Driver Blocks

Memory-Mapped Devices