National Instruments SCXI-1121 Manuel D’Utilisation

Page de 162
Chapter 3
Theory of Operation
© National Instruments Corporation
3-19
Figure 3-9.  Single-Module Multiplexed Scanning (Indirect)
Multiple-Module Multiplexed Scanning
In this mode, all the modules tie into Analog Bus 0, and SCANCON 
enables the output of their amplifiers. The module that is directly cabled to 
the data acquisition board sends SCANCLK onto TRIG0 for the other 
modules and Slot 0, as illustrated in Figure 3-10. The scan list in Slot 0 is 
programmed with the sequence of modules and the number of samples per 
entry.
Figure 3-10.  Multiple-Module Multiplexed Scanning
Cable 
Assembly
Data Acquisition  Board
Analog Input
Timing Output
Other 
Module
Analog Bus 0
SCANCON X
TRIG0
SCANCLK
MCH0
SCXI-1000 or SCXI-1001 Chassis
SLOT X
SLOT 0
SCXI-1121
SCANCLK
MCH0
Cable Assembly
Data Acquisition  Board
Analog 
Input
T
iming 
Output
SLOT A
SLOT B
SLOT 0
SLOT X
TRIG0
SCANCON A
SCANCON B
SCANCON X
SCXI-1000 or SCXI-1001 Chassis
Analog Bus 0
SCXI Module
SCXI Module
SCXI Module