Appendix E Modifying and Installing I/O Expansion Boards© National Instruments Corporation E-5 VXIpc 800 Series User ManualLength of VXIpc-860 Plug-In BoardsThe VXIpc-860 can accommodate PCI or ISA I/O boards that are up to4.2 in. high and up to 8.4 in. long. When DRAM SIMMs 0.85 in. areused on the processor board, the component-side component height ona 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-sidecomponent 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 interferewith ISA cards than PCI cards, the two are discussed separately in thefollowing sections.Length of PCI Plug-In BoardsThe VXIpc-860 accommodates any 32-bit, 5 V PCI I/O boards that area maximum of 8.4 in. long with the standard height of 4.2 in. (seeFigure E-5). PCI cards are installed in the VXIpc-860 such that theboard components face the processor board, which contains theprocessor and system RAM. PCI components (higher than 0.48 in. inthe area shown in Figure E-4) on a plug-in board may physically contactthe 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-860Because larger DRAM sizes may employ taller SIMMs, you must becareful that the component height of the PCI board does not interferewith the SIMMs in such a way that electrical shorts occur or that the PCIboard is stressed enough to compromise its physical or electricalintegrity.PCI Card Heat SinkRiser CardFront Panel Possible SupportBracket Positions.85 in. HighSIMMs.48 in.VXI Connector8.4 in. max
