Hardware Configuration and Installation
Chapter 2
VXI-AT2000/NI-VXI MS-DOS Getting Started
2-20
© National Instruments Corporation
device, such as a PC AT computer with an AT-MXI interface, attempts a transfer that maps into
the VXIbus mainframe.
The VXI-MXI uses VMEbus request level 3 in its factory default setting, as required by the
VXIbus specification. This is suitable for most VXIbus systems. However, you can change the
VXI-MXI to use any of the other three request levels (0, 1, or 2) by changing the jumper
configuration on the jumper blocks labeled VMEbus Request Level on the front panel. You may
want to change request levels to change the priority of the VXI-MXI request signal. For more
information, refer to the VMEbus specification.
To change the VMEbus request level of the VXI-MXI, rearrange the jumpers on the pin arrays as
shown in Figure 2-11.
a. Level 3 Requester (default)
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VMEbus Request Level
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b. Level 2 Requester
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c. Level 1 Requester
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d. Level 0 Requester
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Figure 2-11. VXI-MXI VMEbus Requester Jumper Settings
