Install the QDC Module
Chapter 2
2-9
Analog inputs and outputs are sensitive to electrical noise interference.
Take care to shield them properly.
Guidelines:
Use 22-gage (or larger) twisted-pair cable, 100% shielded with drain
wire, such as Belden 8761 (or equivalent). For cable distances over
50 ft, use 18-gage cable such as Belden 8760 (or equivalent)
Ground the cable shield at one end only; generally at the sensor or
amplifier end, not at the I/O chassis (see Figure 2.4 and Figure 2.5)
Figure 2.4
Shielding
Differential Inputs
Connect the cable shield
and case ground to earth
ground at the Input Sensor
Input Sensor
18
17
14
QDC Module Input
+
–
109103
+15V
-15V
Do not connect.
Test purposes,
only.
10G
22M
22M
18v 18v
Ground and Shield
Your I/O Devices