Appendix D Common Questions
© National Instruments Corporation D-3 PCI-MXI-2 for Linux
Are the PCI-MXI-2 and the VXI-MXI-2 two devices or one with
respect to the VXIbus?
Both the PCI-MXI-2 and the VXI-MXI-2 are unique VXIbus devices with
their own logical addresses. However, the MXIbus allows the computer to
behave as if it is inside the chassis with the VXI-MXI-2 by transparently
converting PCI bus cycles to MXIbus cycles to VXIbus cycles, and
vice versa.
I have a system that requires rugged chassis and bulkhead cables.
Can I still use MXIbus?
Yes, National Instruments sells MXIbus bulkhead cables. Contact National
Instruments for further 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 VXIbus backplane. However, the
oscillator for the VXI-MXI-2 and the EXTCLK input from the front panel
use TTL. Therefore, you need to supply a TTL level signal for EXTCLK
and our voltage converters will convert the signal to differential ECL.
CLK10 is not applicable to VME.
What is the accuracy of the CLK10 signal?
The CLK10 generated by the VXI-MXI-2 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 VXI-MXI-2.
CLK10 is not applicable to VME.
Whenever I try to execute any of the NI-VXI utilities, I receive a
message similar to this one:
error in loading shared libraries: libnivxi.so: cannot
open shared object file: no such file or directory
What does this error message mean?
This usually means that the application could not load the NI-VXI library.
Check the environment variable NIVXIPATH and your /etc/
ld.so.conf file. NIVXIPATH should be set only to the directory where
you installed NI-VXI (/usr/local/nivxi by default).
/etc/ld.so.conf should include the directory where you installed the
NI-VXI library (/usr/local/nivxi/lib by default). Run ldconfig to
reread this file.