National Instruments 800 Series - Manual (Page 83)

© National Instruments Corporation F-1 VXIpc 800 Series User Manual
Appendix
F
Common Questions
This appendix answers common questions you may have when using
the VXIpc 800 Series.
What do the LEDs on the front of the VXIpc 800 mean?
Refer to Appendix C, LED Indicators, for a description of the front
panel LEDs.
Is something wrong with the VXIpc 800 if the red SYSFAIL and
FAILED LEDs stay lit after booting the VXIpc 800?
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 800?
Yes. The VXIpc 800 uses the 32-bit PCI bus to interface to the VXIbus.
In fact, the VXIbus circuitry on the VXIpc 800 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 800 and the EXTCLK input on the VXIpc-800
front panel use TTL levels; therefore, 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 800 is ±100 ppm (0.01%) as
per the VXIbus specification. If you need a more accurate CLK10 signal
on the VXIpc 800 Series, you can use the EXTCLK connector on its
front panel.