© National Instruments Corporation
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VXIpc-850 Series User Manual
Common Questions
F
Appendix
This appendix answers common questions you may have when using
the VXIpc-850.
What do the LEDs on the front of the VXIpc- 850 mean?
Refer to Appendix C, LED Indicators , for a description of the front
panel LEDs.
Is something wrong with the VXIpc-850 if the red SYSFAIL and FAILED LEDs
stay lit after booting the VXIpc-850?
If either the SYSFAIL or FAILED LED remains lit, refer to
Appendix C, LED Indicators , for troubleshooting steps.
Can I access 32-bit registers in my VXIbus system from the VXIpc -850?
Yes. The VXIpc-850 uses the 32-bit PCI bus to interface to the
VXIbus . In fact, the VXIbus circuitry on the VXIpc-850 also supports
the new VME64 standard for D64 accesses . Refer to your VXI
software manual for more information.
What kind of signal is CLK10 and what kind of signal do I need for an external
CLK10?
CLK10 is a differential ECL signal on the backplane. However, the
oscillator for the VXIpc-850 and the EXTCLK input from the front
panel use TTL levels; t herefore, you need to supply a TTL-level signal
for EXTCLK. Our voltage converters convert the signal to differential
ECL.
What is the accuracy of the CLK10 signal?
The CLK10 signal generated by the VXIpc-850 is
±
100 ppm (0.01%)
as per the VXIbus specification. If you need a more accurate CLK10
signal, you can use the EXTCLK input at the front of the VXIpc-850.
