National Instruments VXI-1394 - Manual (Page 57)

Appendix D Common Questions
VXI-1394 User Manual for Windows D-4 ni.com
What should I do if I get a Configuration EEPROM is Invalid
message?
There are several reasons why you might get the Configuration EEPROM
is Invalid message. For example, if you turned off the VXI chassis
while the configuration update process was still in progress, the board
functions normally except when running MAX. To correct these problems,
reboot the VXI chassis with the Load Factory switch set (as described in
Appendix C,
Advanced Hardware Configuration Settings ) and update the
configuration, or load the configuration from file.
What do the LEDs on the front of the VXI-1394 mean?
• The SYSFAIL LED shows the state of the VXI/VMEbus SYSFAIL
line. This line is asserted whenever any device in the chassis has not
yet passed its self test, if it has failed its self test, or if it has detected a
failure after originally passing its self test.
• The 1394 LED indicates that the VXI-1394 is being accessed by
another device on the IEEE 1394 bus, such as when the computer
communicates with either the VXI-1394 or another device in the
chassis.
• The VXI LED, when lit, indicates that the VXI-1394 is being accessed
by another device in the VXI chassis, such as when a bus master inside
the chassis wants to talk to either the VXI-1394 or memory in the
computer.
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 VXIbus backplane. However, the
oscillator for the VXI-1394 and the EXTCLK input from the front panel
use TTL. Therefore, supply a TTL-level signal for EXTCLK, and onboard
voltage converters will automatically convert the signal to differential ECL.
What is the accuracy of the CLK10 signal?
The CLK10 generated by the VXI-1394 is 1% accurate. If you need a more
accurate CLK10 signal, you can use the EXTCLK input at the front of the
VXI-1394.