Chapter 2
Connecting Signals
©
National Instruments Corporation
2-11
Rear Signal Connector Descriptions
The rear signal connector on the cabled module is the interface between
the DAQ device and all modules in the SCXI chassis. AI 0 is used to
differentially multiplex all 16 channels, the CJ sensor, and analog signals
from the modules to the connected DAQ device.
The communication signals between the DAQ device and the SCXI system
are listed in Table 2-4. If the DAQ device is connected to the SCXI-1503,
these digital lines are unavailable for general-purpose digital I/O.
Table 2-4.
SCXI-1503 50-Pin Rear Connector Signals
Pin
SCXI
Signal Name
NI-DAQmx
Device Signal
Name
Direction
Description
1, 2
AI GND
AI GND
—
Analog input ground—connects to
the analog input ground of the DAQ
device.
3
AI 0 +
AI 0 +
Input
Channel 0 positive—used to
differentially multiplex all
16 channels, the CJ sensor, and
analog signals from the modules to
the connected DAQ device.
4
AI 0 –
AI 0 –
Input
Channel 0 negative—used to
differentially multiplex all
16 channels, the CJ sensor, and
analog signals from the modules to
the connected DAQ device.
24, 33
DIG GND
D GND
—
Digital ground—these pins supply
the reference for E/M Series DAQ
device digital signals and are
connected to the module digital
ground.
25
SER DAT IN
P0.0
Input
Serial data in—this signal taps into
the SCXIbus MOSI line to send
serial input data to a module or
Slot 0.
