National Instruments 800 Series - Manual (Page 76)

Appendix E Modifying and Installing I/O Expansion Boards
© National Instruments Corporation E-5 VXIpc 800 Series User Manual
Length of VXIpc-860 Plug-In Boards
The VXIpc-860 can accommodate PCI or ISA I/O boards that are up to
4.2 in. high and up to 8.4 in. long. When DRAM SIMMs 0.85 in. are
used on the processor board, the component-side component height on
a PCI I/O board shall be 0.48 in. tall in the area shown in Figure E-4.
For the same height DRAM SIMMs, the ISA I/O board solder-side
component height shall be 0.07 in. tall in the area shown in Figure E-4.
Be sure to allow for clearance if you want to use taller DRAM SIMMs.
Because DRAM SIMMs taller than 0.85 in. 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-860 accommodates any 32-bit, 5 V PCI I/O boards that are
a maximum of 8.4 in. long with the standard height of 4.2 in. (see
Figure E-5). PCI cards are installed in the VXIpc-860 such that the
board components face the processor board, which contains the
processor and system RAM. PCI components (higher than 0.48 in. in
the area shown in Figure E-4) on a plug-in board may physically contact
the DRAM SIMMs installed on the CPU card, as shown in Figure E-5.
Figure E-5. Length Restrictions for PCI Plug-In Boards Used with the VXIpc-860
Because larger DRAM sizes may employ taller SIMMs, you must be
careful that the component height of the PCI board does not interfere
with the SIMMs in such a way that electrical shorts occur or that the PCI
board is stressed enough to compromise its physical or electrical
integrity.
PCI Card Heat Sink Riser Card
Front Panel Possible Support
Bracket Positions
.85 in. High
SIMMs
.48 in.
VXI Connector
8.4 in. max