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National Instruments Corporation
5
SCC-AI Series Isolated Analog Input Modules
Connecting the Input Signals
The SCC-AI
XX
has a fixed screw-terminal receptacle and a removable
screw-terminal block, as shown in Figure 1-2.
Figure 1-2.
SCC-AI
XX
Two-Part Screw-Terminal System
After you install the SCC-AI
XX
, connect the input signals to the removable
screw-terminal block of the module.
1.
Remove power from the signal lines.
2.
Strip 7 mm of insulation from the ends of the signal wires.
3.
Insert the wires into the screw terminals.
4.
Tighten the screws to 0.5 to 0.6 N · m (4.4 to 5.3 lb - in.) of torque.
Each screw terminal is labeled by pin number <1..4>. Pins 1 and 2 form a
channel routed to E Series DAQ device channel
X
+
8, and pins 3 and 4 form
a channel routed to the E Series DAQ device channel
X
, where
X
is 0 to 7
depending on the socket where you plug in the module. The SCC-AI
XX
provides channel-to-ground and module-to-module isolation only. It does
not provide isolation between the two channels of the SCC-AI
XX
. Because
both channels must have the same reference voltage, pins 1 and 3 are
connected together internally. Figure 1-3 shows the SCC-AI
XX
signal
connections.
1
SCC Screw-Terminal Receptacle
2
Removable Screw-Terminal Block
3
2
1
4
1
2