Chapter 3 Configuration and Default Settings
© National Instruments Corporation 3-27 NI VXIpc-882 User Manual
Front Panel SMB ExtClk Setup
The NI VXIpc-882 computers have an SMB connector on the front panel
for an external clock. Onboard programmable logic can configure the
NI VXIpc-882 to drive its 10 MHz VXI CLK10 signal to this connector as
an output or to use this connector as an input for the 10 MHz VXI CLK10
signal. In this fashion, you can configure multiple mainframes to operate
off a single 10 MHz system clock. Refer to the VXIbus CLK10 Routing
section for information on properly configuring the hardware to use the
CLK10 routing feature of the NI VXIpc-882.
Front Panel SMB TRGIN/TRGOUT
The NI VXIpc-882 gives programmers full hardware and software control
over the VXI trigger lines. The NI VXIpc-882 has two SMB trigger I/O
connectors on its front panel for routing any of the TTL trigger lines
between the backplane and external devices. The VXI trigger interface is
based on the advanced MANTIS ASIC developed by National Instruments.
The MANTIS provides the complete NI VXIpc-882 VXI interface to the
outer rows of the P2 backplane connector in a single chip. The
NI VXIpc-882 can respond to all VXI-defined protocols on all P2 TTL and
ECL trigger lines at the same time. The MANTIS features an internal
cross-matrix switching system for routing between lines as well as to and
from the front panel and onboard clocks. An internal counter gives
sophisticated counting of events and interrupting on trigger edges and
pulses, as well as generating pulse trains, variable length pulses, and pulse
stretching.
You have the option to terminate the external trigger input SMB with 50 Ω
to ground to match the driving source, if necessary. Use MAX to set this
option.