Appendix E
Modifying and Installing I/O Expansion Boards
VXIpc -850 Series User Manual
E- 2
© National Instruments Corporatio n
Length of VXIpc-850 Plug-In Boards
The VXIpc-850 will easily accommodate any PCI or ISA I/O boards
that are 4.2 in. high or less and are 7.72 in. in length or less . If you want
to install a longer board, you must consider several conditions such as
handling, vibration, and possible contact with the system DRAM
SIMMs.
When you install a plug-in board, the front end of the board that sticks
out of the VXIpc-850 front panel is firmly supported , because it is
screwed to the front panel of the VXIpc-850. Longer boards cannot be
firmly supported away from the front panel; therefore, if your system
requires rugged handling or resides in a high vibration environment,
plug-in boards longer than 7.72 in. are not recommended.
The restrictions on the length of a VXIpc-850 plug-in board also
depend on the possibility of physical contact with the system DRAM
SIMMs . Because the DRAM SIMMs are more likely to interfere with
ISA cards than PCI cards, the two are discussed separately in the
following sections.
Length of PCI Plug-In Boards
The VXIpc-850 should accommodate any standard 32-bit, 5 V PCI I/O
board . The maximum standard dimensions of a PCI I/O board are
12.283 in. by 4.2 in. PCI cards are installed in the VXIpc-850 such that
the board components face the processor card, which contains the
processor and system RAM . Exceptionally tall PCI components on a
plug-in board may physically contact the DRAM SIMMs installed on
the CPU card of the VXIpc-850, as shown in Figure E-2.
PCI Card
Riser Card
Heat Sink
Front Panel
Support Brackets
SIMMs
VXI Connector
.62 in. max to Heat Sink
.32 in. max to SIMMs
Figure E- 2. Component Height Restrictions on PCI Plug-In Boards