Rockwell Automation 61C23 AutoMate Local I/O Head - Manual (Page 18)

5Ć2
5.2 The COM LED Is Off
Problem: The COM LED on the faceplate is off. When lit, this LED
signifies that there is communication between the Local I/O Head and
the processor or Remote I/O Head to which it is connected. It should
be on if communication is taking place. The possible causes of this
problem are incorrect configuration, a disconnected or
malfunctioning Local I/O Interface cable, a malfunctioning processor
or Remote I/O Head, a rail fault, or a malfunctioning Local I/O Head.
Follow the steps below to isolate the problem.
Step 1.
Verify that the configuration of the Local I/O Head is
correct and that no errors have been logged in the error
registers. Refer to section 4.0 for more information on
configuration. Refer to JĆ3120 or JĆ3150 for more
information about error registers in the AutoMate 20 and
AutoMate 30 or 40 processors, respectively.
Step 2. Stop any application programs that are running.
Step 3. If a RAIL FAULTLED on the Local I/O Head is on,
troubleshoot the indicated Rail.
Step 4. Examine the processor or Remote I/O Head to which the
Local I/O Head is connected. If the LED indicating power
is off, check the power being supplied to the unit. If power
is sufficient and the LED is off, replace the processor or
Remote I/O Head.
Step 5. Verify that the connections on both ends of the Local I/O
Interface cable are tight.
Step 6. Turn off power to the Local I/O Head and the processor or
Remote I/O Head. Remove the Local I/O Interface cable.
Verify that there are no bent pins on the cable connectors
or I/O ports.
Step 7. Replace the Local I/O Interface cable. If the problem is still
not corrected, replace the Local I/O Head.
5.3 RAIL FAULT LEDs Are On
Problem: One or all of the RAIL FAULTLEDs are on and outputs from
the corresponding Rails are off. The possible causes of this problem
are a disconnected or malfunctioning I/O Rail cable, a malfunctioning
Rail, or a malfunctioning Local I/O Head.
In DCS 5000/AutoMax systems, a rail fault of the Local I/O Head (M/N
61C22A or 61C23) will be indicated in register 4 (drop status) of the
M/N 57C416 Remote I/O Communications module. For earlier
versions of the Local I/O Head (61C22 or 45C22) the RAIL FAULT
LEDs need to be used to diagnose rail faults as described below.
Step 1.
Stop any application tasks that are running and turn off
power to the Local I/O Head.
Step 2. Try to clear the condition by disconnecting and then
reĆconnecting the I/O Rail cable(s) and the Local I/O
Interface cable. Make certain the connections are tight.
Verify that the cables are the correct cables, i.e., M/N 45C5
between the Head and the Rails, and M/N 45C8 between
the Head and the host.