National Instruments MXI-2 Reference Manual page 36

Chapter 5 VXI-MXI-2 Configuration and Installation
From onboard oscillator
W3
From SMB (S3 must be set to "IN")
From MXIbus
a. CLK10 Generated from Onboard Oscillator (Default)
From onboard oscillator
W3
SMB CLK10 Direction From SMB (S3 must be set to "IN")
From MXIbus
b. CLK10 Generated from SMB
From onboard oscillator
W3
From SMB (S3 must be set to "IN")
Receive CLK10 from MXIbus From MXIbus
S7
c. CLK10 Generated from MXIbus
Figure 5-4. VXIbus CLK10 Routing
Notice that Figure 5-4b and Figure 5-4c also show switches S3 and S7,
respectively. You must configure these switches as shown when using the
corresponding CLK10 source setting of W3.
You can also configure the VXI-MXI-2 to drive the external CLK SMB
signal from the VXIbus CLK10 signal. Switch S3 controls whether the
VXI-MXI-2 drives or receives the external CLK SMB signal. If you change
the S3 setting to drive CLK10 out the external CLK10 SMB connector, do
not set the W3 jumper to receive the SMB CLK10 signal; instead, use the
settings shown in either Figure 5-4a or Figure 5-4c as appropriate.
© National Instruments Corporation 5-7 MXI-2 Configuration Reference Manual