Rockwell Automation 57C402 25-115V AC/DC Low Power Output Module - Manual (Page 17)

5Ć1
5.0 DIAGNOSTICS AND
TROUBLESHOOTING
This section explains how to troubleshoot the module and field
connections.
5.1 Incorrect Data
Problem: The device connected to the output is either always off,
always on, or actingdifferent than expected. The possible causes of
this are a module in the wrongslot, a programmingerror, or a
malfunctioningmodule. It is also possible that the output is either not
wired or wired to the wrongdevice. Use the followingprocedure to
isolate the problem:
Step 1.
Verify that the output module is in the correct slot and that
the I/O definitions are correct.
Refer to figure 3.2. Verify that the slot number being
referenced agrees with the slot number defined in the
configuration. Verify that the register number is 0. Verify
that the bit number refers to the proper bit. Note that the
bit number and the wire number are not the same.
For remote I/O installations, also verify that the master slot
and remote drop number are defined correctly.
Step 2. Verify that the power supply is functional.
Confirm that all connections at the terminal strip are tight.
Connect a voltmeter to the proper points on the terminal
strip and toggle the device. The voltmeter should alternate
between 0 and 115 volts. If this does not happen, there is
a problem with either the external device, the DC power
supply, or the wiringto the terminal strip.
Connect the programming terminal to the system and run
the ReSource software.
Stop all tasks that may be running.
Confirm that all connections at the terminal strip are tight.
Connect a voltmeter to the power supply connections on
the terminal strip. If the voltage is not correct, there is a
problem with the power supply or the wiringto the
terminal strip.
Check the cable for continuity between the faceplate
connector and the terminal strip.
Step 3. Verify that the module can be accessed.
Connect the programming terminal to the system and run
the ReSource Software.
Stop all tasks that may be running.
Use the I/O MONITOR function. Toggle the output device
and determine whether the bit is changing state by
observingthe condition of the LED on the module. If the
LED does not change state, the hardware is
malfunctioning.