Chapter 6 NI-VXI Configuration Utility
© National Instruments Corporation 6-15 PCI-MXI-2 for Linux
You can select the Yes or No options to manually determine whether the
PCI-MXI-2 should be the MXIbus System Controller. You must still be
certain to cable the MXIbus system appropriately when you make either of
these selections.
Note Make sure the MXI-2 cable is connected to the PCI-MXI-2 when you poweron or
reboot the computer. This is required for the PCI-MXI-2 to automatically detect whether it
will be the MXIbus System Controller.
MXI Bus Timeout
The MXIbus Bus Timeout (BTO) is a watchdog timer for transfers on the
MXIbus. The MXIbus BTO operates only when the PCI-MXI-2 is acting
as the MXIbus System Controller.
After the specified amount of time has elapsed, the BTO circuitry
terminates a MXIbus cycle if no slave has responded. The BTO is also
disabled when the current MXIbus cycle maps to the VXI/VMEbus through
a VXI/VME-MXI-2.
The default timeout value is 1ms. If the Enable MXI-2 Auto Retry
checkbox option is enabled, you should use a MXI Bus Timeout of 1ms
or greater.
MXI CLK10
The PCI-MXI-2 is capable of either receiving or driving the MXIbus
CLK10 signal.
You can use the Drive or Receive options of the MXI CLK10 feature to
control the direction of the MXIbus CLK10 signal. By default all MXI-2
boards receive MXI CLK10 (the Receive option is active); therefore, you
must choose one board on your MXI-2 bus to drive CLK1 0 by changing the
value of the control to Drive. For most configurations, it is recommended
to choose the System Controller as the CLK10 source for simplicity.
Theonly exception you may want to make is if you want your triggers
synchronous to the VXI 10MHz clock.
Caution Do not configure more than one MXIbus device to drive MXIbus CLK10. Having
a second device driving MXIbus CLK10 could damage the device.