Chapter
6 NI-VXI
Configuration
Utility
6-26
ni.com
MXI Bus Options
Use the options in this group to control features of the MXIbus interface on
the VXI/VME-MXI-2 module.
MXI Bus System Controller
You can use the
System Controller
control to determine whether the
VXI/VME-MXI-2 acts as the MXI Bus System Controller. When the
Auto
setting (the default setting) is active, the VXI/VME-MXI-2 automatically
can sense from the MXIbus cable whether it should be the controller.
You can select either
Yes
or
No
to manually determine if the
VXI/VME-MXI-2 should be the MXI Bus System Controller. You must
still be certain to cable the MXIbus system appropriately when you make
either of these selections.
MXI Bus Timeout Value
The MXI Bus Timeout (BTO) is a watchdog timer for transfers on
the MXIbus. The MXIbus BTO unit operates only when the
VXI/VME-MXI-2 is acting as the MXI Bus System Controller. The
functionality of this control is similar to that of the
VXI Bus Timeout
control described in the
section. The options range
from 8
µ
s to 128 ms, with a default value of 1 ms.
After the specified amount of time has elapsed, the BTO circuitry
terminates a MXIbus cycle if no slave has responded. The BTO circuitry is
automatically deactivated when the VXI/VME-MXI-2 is not acting as the
MXI Bus System Controller. The BTO is also disabled when the current
MXIbus cycle maps to the VXI/VMEbus through a VXI/VME-MXI-2.