National Instruments MXI Series, Начало работы

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Chapter 3 VXI-MXI-2 Configuration and Installation
© National Instruments Corporation 3-13 PCI-MXI-2 for Linux
Figure 3-8. SMB Trigger Input Termination
MXIbus Termination
The first and last MXIbus devices connected to the MXIbus—whether it is
a single MXI-2 cable or daisy-chained MXI-2 cables—must terminate the
MXIbus. Any MXIbus devices in the middle of a MXIbus daisy chain must
not terminate the MXIbus.
The VXI-MXI-2 automatically senses whether it is at either end of the
MXIbus cable to terminate the MXIbus. You can manually control MXIbus
termination by defeating the automatic circuitry. Use switches 1 and 2
of the four-position switch at location U35 to control whether MXIbus
termination is automatic (Figure 3-9a), on (Figure 3-9b), or off
(Figure 3-9c). The settings of switches 3 and 4 have no effect on MXIbus
termination.
Use switch 2 of U35 to select whether you want the VXI-MXI-2 to
automatically control termination of the MXIbus. Switch 1 of U35 lets
a. Non-Terminated External Trigger Input SMB (Default)
b. Terminated External Trigger Input SMB with 50
Ω
S2 Off
On 50
Ω
Termination for External Trigger Input
S3 Out
In
S4 Off
On
NON-INVERTED
INVERTED
S5
SMB CLK10 Direction
50
Ω
Termination for SMB CLK10 (Effective only when S3 is set to “IN”)
SMB CLK10 Output Polarity (Effective only when S3 is set to “OUT”)
50
Ω
Termination for SMB CLK10 (Effective only when S3 is set to “IN” )
S2 Off
On 50
Ω
Termination for External Trigger Input
S3 Out
In
S4 Off
On
NON-INVERTED
INVERTED
S5
SMB CLK10 Direction
SMB CLK10 Output Polarity (Effective only when S3 is set to “OUT”)