Chapter 1 Introduction
NI 781xR User Manual 1-2 ni.com
You can add additional I/O channels and signal conditioning using the
CompactRIO R Series Expansion Chassis and CompactRIO I/O modules.
Refer to Appendix A, Specifications, for detailed NI 781xR specifications.
Using PXI with CompactPCIUsing PXI-compatible products with standard CompactPCI products is an
important feature provided by PXI Hardware Specification Revision 2.1
and PXI Software Specification Revision 2.1. If you use a PXI-compatible
plug-in card in a standard CompactPCI chassis, you cannot use
PXI-specific functions, but you still can use the basic plug-in card
functions. For example, the RTSI bus on the R Series device is available in
a PXI chassis, but not in a CompactPCI chassis.
The CompactPCI specification permits vendors to develop sub-buses that
coexist with the basic PCI interface on the CompactPCI bus. Compatible
operation is not guaranteed between CompactPCI devices with different
sub-buses nor between CompactPCI devices with sub-buses and PXI.
The standard implementation for CompactPCI does not include these
sub-buses. The R Series device works in any standard CompactPCI chassis
adhering to the PICMG CompactPCI 2.0 R3.0 core specification.
PXI-specific features are implemented on the J2 connector of the
CompactPCI bus. Table1-1 lists the J2 pins used by the NI PXI-781xR.
The NIPXI-781 xR is compatible with any CompactPCI chassis with a
sub-bus that does not drive these lines. Even if the sub-bus is capable of
driving these lines, the R Series device is still compatible as long as those
pins on the sub-bus are disabled by default and are never enabled.
Caution Damage can result if the J2 lines are driven by the sub-bus.