User`s guide

15 Frequently Asked Questions
If you have or want to us e multiple board s of a particular type in your
system, ensure that the I/O drive supports multiple boards. Refer to one
of the following:
• xPC Target I/O Reference
• xPC Target Interactive Hardware Selection Guide
(
http://www.mathworks.com/support/product/XP/productnews
/interactive_guide/xPC_Target_Interactive_Guide.html
)
If you confirm that the board type supports multiple boards, and these boards
are installed in the xP C Target system, p erform the following procedure to
obtain the bus and slot information for these boards:
1 In the PCI devices display, note the contents of the Bus and Slot columns
of the PCI devices in which you are interested.
2 Enter the bus and slot numbers as vectors into the PC I Slot parameter of
the PCI device. For example
[1 9]
where 1 is the bus number and 9 is the slot num ber.
For additional information about PCI bus I/O devices, refer to the “PCI Bus
I/O Devices” section of xPC Target I/O Reference.
What Sample Time Can I Expect from the xPC Target
Software?
The xPC Target kernel is tuned for minimal overhead and maximum
performance. On the target PC, the k ernel dedicates all of its resources to
the target application. For some representative sample time numbers, run
xpcbench at the M ATLAB command line.
Actual obtainab le sample times depend on a number of factors, including:
• Processor performance
• Model complexity
• I/O block types
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