System wiring guidelines – Rockwell Automation 1769-OF8V CompactLogix Analog Output Module User Manual
Page 12
12 CompactLogix Analog Output Module
Rockwell Automation Publication 1769-IN089A-EN-P - March 2011
System Wiring Guidelines
Consider the following when wiring your system:
•
All module commons (ANLG COM) are connected in the analog
module. The analog common (ANLG COM) is not connected to earth
ground inside the module.
•
Channels are not isolated from each other.
•
Use Belden 8761, or equivalent, shielded wire.
•
Under normal conditions, the drain wire and shield junction must be
connected to earth ground, via a panel or DIN rail mounting screw at
the analog I/O module end. Keep the shield connection to ground as
short as possible.
(1)
•
To ensure optimum accuracy, limit overall cable impedance by keeping
your cable as short as possible. Locate the I/O system as close to your
sensors or actuators as your application will permit.
•
Current outputs (Iout 0+ to Iout 7+) of the 1769-OF8C module source
current that returns to ANLG COM. Load resistance for a current
output channel must remain between 0…500 Ω.
•
Voltage outputs (Vout 0+ to Vout 7+) of the 1769-OF8V module are
referenced to ANLG COM. Load resistance for a voltage output
channel must be equal to or greater than 1K W.
WARNING: EXPLOSION HAZARD
All wiring must comply with N.E.C. article 501-4(b).
(1)
In environments where high frequency noise may be present, it may be necessary to ground the shield
via a 0.1µF capacitor at the load end and also ground the module end without a capacitor.
IMPORTANT
To comply with UL restrictions, this equipment must be powered from a
source compliant with Class 2 or Limited Voltage/Current.