Rockwell Automation 1746-NO8V SLC 500 8-Point Analog Output Module/ User Manual - Manual (Page 53)

1 Publication 1746-UM026A-EN-P - September 2003
Chapter
6
Module Diagnostics and Troubleshooting
Read this chapter to prevent potential problems. This chapter covers:
•
inspecting your module
•
disconnecting prime movers
•
power-up diagnostics
•
interpreting the LED indicators
•
interpreting I/O error codes
•
troubleshooting
Before testing your module, test your SLC 500 system using the
procedures described in your controller’s User Manual.
Inspecting Your Module You can prevent many potential problems by inspecting the module:
1. Ensure that the external 24V dc jumper, J4, is set properly:
•
With the jumper in the RACK position, the module draws all
its power from the backplane of the SLC system.
•
With the jumper in the EXT position, the module draws its
24V dc power from an external power source; however, the
module still draws its 5V dc power from the backplane.
•
If the J4 jumper is missing, the module will report a 24V dc
power fail, regardless of whether external 24 V dc power is
present or not.
2. Ensure that all wire connections are correct and secure and that
no wires are missing or broken. See Chapter 2, Installation and
Wiring, for more information.
3. Ensure that the shield for the cable used to wire your module is
properly grounded.
4. Ensure that the removable terminal block on your module is
secure.
IMPORTANT
If your module appears to be functioning, but the
terminals are not providing an output signal, the 24V
dc power source (backplane or external) may not be
providing enough current. Current consumption at
24V dc is 250 mA for the 1746-NO8I and 160 mA for
the 1746-NO8V.