Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set User Manual
Page 581

I/O Interface
Section 10A
10A-58
voltages on IN+ and IN-- terminals terminals must remain within ±20
Volts with respect to ANL COM for proper input channel operation.
This is true for current and voltage input channel operation.
voltage outputs (OUT 0 and OUT 1) are referenced to ANL COM.
Load resistance (R1) for a voltage output channel must be equal to or
greater than 1K ohms.
current output channels (OUT 0 and OUT 1) source current that returns
to ANL COM. Load resistance (R1) for a current output channel must
remain between 0 and 500 ohms.
input connections for single-ended or differential inputs are the same.
ATTENTION: Before wiring any analog module, disconnect
power from the chassis and from any other source to the analog
module.
Grounding Your Cable
Belden cable #8761 has two signal wires (black and clear), one drain wire
and a foil shield. The drain wire and foil shield must be grounded at one
end of the cable. Do not earth ground the drain wire and foil shield at both
ends of the cable.
Input Channel -- Ground the drain wire and foil shield near the sourcing
device.
Output Channel -- Use a rack mounting tab as a ground for the drain wire
and foil shield.
Important: If you cannot ground the input channel at the sourcing device,
ground the drain wire and foil shield at the rack mounting tab. Do not
connect the foil shield or drain wire to the analog terminal block. They
must be connected to an earth ground, which is not provided at the analog
module.