Chapter 4
Theory of Operation
©
National Instruments Corporation
4-3
SCXIbus Connector and Digital Interface
Figure 4-2 shows a diagram of the SCXI-1120/D and SCXIbus digital
interface circuitry.
Figure 4-2.
Digital Interface Circuitry Block Diagram
The digital interface circuitry is divided into a data acquisition section
and an SCXIbus section. The SCXI-1120/D connects to the SCXIbus
through a 4
×
24 metral receptacle and to the DAQ device through a 50-pin
ribbon-cable header. The digital interface circuitry buffers the digital
signals from the DAQ device and the SCXIbus and sends signals back and
forth between the DAQ device and the SCXIbus.
SCXIbus
Digital Interface
SERDATOUT
SERCLK
SLOT0SEL*
DAQD*/A
SERDATIN
Buffered Serial
Data
Buffered Digital
Signal Controls
Rear Connector
MISO
SPICLK
INTR*
D*/A
MOSI
SS*
