Rockwell Automation 1769-OF4 Compact I/O Analog Output Module - Manual (Page 11)

Compact I/O Analog Output Module 11
Publication 1769-IN087A-EN-P - August 2009
Ground the Module
This product is intended to be mounted to a well-grounded mounting surface such
as a metal panel. Additional grounding connections from the module’s mounting
tabs or DIN rail, if used, are not required unless the mounting surface cannot be
grounded. Refer to Industrial Automation Wiring and Grounding Guidelines,
Allen-Bradley publication
1770-4.1 , for additional information.
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)
•
For 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. (2)
•
Voltage outputs (Vout 0+…Vout 3+) of the 1769-OF4 module are referenced
to ANLG COM. Load resistance for a voltage output channel must be equal
to or greater than 1K
Ω
.
•
Current outputs (Iout 0+…Iout 3+) of the 1769-OF4 module source current
that returns to ANLG COM. Load resistance for a current output channel
must remain between 0 and 600
Ω
.
(1) In environments where high-frequency noise may be present, it may be necessary to directly ground cable shields to earth
at the module end and via a 0.01µF, 2000V capacitor at the sensor end.
(2) Cable length over 50 meters may impact accuracy. For details, refer to the Compact I/O Analog Output Module User
Manual, publication 1769-UM020 .
ATTENTION
Be careful when stripping wires. Wire fragments that fall into a module
can cause damage at power up. Once wiring is complete, make sure the
module is free of all metal fragments.