National Instruments NI PXI-7831R - Manual (Page 10)

Chapter 1 Introduction
NI PXI-7831R User Manual 1-2 ni.com
The PXI chassis has the Real-Time System Integration (RTSI) bus to easily
synchronize several measurement functions to a common trigger or timing
event. The RTSI bus is implemented on the PXI trigger bus on the PXI
backplane. The RTSI bus can route timing and trigger signals between as
many as seven PXI devices in your system.
Refer to Appendix A, Specifications , for detailed specifications of the RIO
device.
Using PXI with CompactPCI
Using 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 can still use the basic plug-in card
functions. For example, the RTSI bus on the RIO 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 RIO device works in any standard CompactPCI chassis
adhering to PICMG CompactPCI 2.0 R3.0.
PXI-specific features are implemented on the J2 connector of the
CompactPCI bus. Table 1-1 lists the J2 pins used by the NI PXI-7831R.
The NI PXI-7831R 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 RIO 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.