Chapter 6 NI-VXI Configuration Utility
© National Instruments Corporation 6-29 PCI-MXI-2 for Linux
Transfer Limit
You can use this feature to control how many data transfers the
VXI/VME-MXI-2 will perform on the MXIbus before releasing it to
another master device that is requesting use of the bus. The default setting
holds the MXIbus for an unlimited period of time.
The other options you can choose from are 16, 64, and 256 transfers. Ifyou
do not want the VXI/VME-MXI-2 to hold the MXIbus for an unlimited
period of time, you can use this control to select one of these values.
Parity Checking
By default, MXIbus parity checking is enabled and should not be disabled
under normal circumstances. MXIbus parity is always generated regardless
if checking is enabled or disabled.
MXI Fair Requester
You can use the Operate as Fair Requester checkbox control to configure
the VXI/VME-MXI-2 as either a fair or unfair requester on the MXIbus. In
its default setting (disabled), the VXI/VME-MXI-2 will request the bus at
any time. If you enable this option, the VXI/VME-MXI-2 will request the
MXIbus only when there are no requests pending from other MXIbus
masters. This prevents other MXIbus masters from being starved of
bandwidth.
MXI CLK10 Signal
The VXI-MXI-2 can either receive or drive the MXIbus CLK10 signal.
Inits default setting, the VXI-MXI-2 uses the switch setting of S7 to
determine the signal direction.
♦VME users—This option is not applicable to the VME-MXI-2.
You can use the Drive or Receive options to override the setting of S7 and
control the direction of the MXIbus CLK10 signal. When receiving the
MXIbus CLK10 signal, configure the W3 jumper setting to use the MXIbus
as the source for generating the VXIbus CLK10 (applicable only if the
VXI-MXI-2 is a Slot0 device). When driving the MXIbus CLK10, the
VXIbus CLK10 is used as the source. In this case, change the jumper
setting so that it does not use the MXIbus CLK10 as the source for the
VXIbus CLK10.
Caution Do not configure more than one MXIbus device to drive MXI CLK10. Setting up
a second device to drive MXI CLK10 could damage the device.