Chapter 4
Theory of Operation
©
National Instruments Corporation
4-5
Analog and Timing Circuitry
The SCXIbus provides analog power (±18.5 VDC) that is regulated on the
SCXI-1120/D to ±15 VDC, a guard, an analog bus (AB0±), and a chassis
ground (CHSGND). AB0± buses the SCXI-1120/D output to other
modules or receives outputs from other modules through the SCXIbus. The
guard guards the analog bus and can be connected through jumper W46 to
the analog ground reference or can be left floating (a connection can be
made by another device).
The DAQ device analog input and timing is the interface between the
SCXI-1120/D output and the DAQ device.