Rockwell Automation 57C421B Pulsetach Input Module/DCS 5000/AutoMax - Manual (Page 43)

5Ć1
5.0 DIAGNOSTICS AND
TROUBLESHOOTING
This section explains how to troubleshoot the module and field
connections. If the problem cannot be corrected by following the
instructions below, the module is not userĆserviceable.
DANGER
ONLY QUALIFIED ELECTRICAL PERSONNEL FAMILIAR WITH THE
CONSTRUCTION AND OPERATION OF THIS EQUIPMENT AND THE HAZARDS
INVOLVED SHOULD INSTALL, ADJUST, OPERATE, OR SERVICE THIS
EQUIPMENT. READ AND UNDERSTAND THIS MANUAL AND OTHER
APPLICABLE MANUALS IN THEIR ENTIRETY BEFORE PROCEEDING. FAILURE
TO OBSERVE THIS PRECAUTION COULD RESULT IN SEVERE BODILY INJURY
OR LOSS OF LIFE.
5.1 Incorrect Data
The data is either always off, always on, or different than expected.
When this happens the module is malfunctioning, is in the wrong
slot, or there is a programming error. It is also possible that the input
wiring is incorrectly connected.
WARNING
INSERTING OR REMOVING A MODULE OR ITS CONNECTING CABLES MAY
RESULT IN UNEXPECTED MACHINE MOTION. TURN OFF POWER TO THE RACK
BEFORE INSERTING OR REMOVING A MODULE OR ITS CONNECTING CABLES.
FAILURE TO OBSERVE THESE PRECAUTIONS COULD RESULT IN BODILY
INJURY.
Use the following procedure to isolate the error:
Step 1.
Verify that the Pulsetach Input module is in the correct
slot as defined in the configuration.
Step 2. Verify that the pulsetach inputs are wired correctly.
Confirm that all terminal strip connections are tight.
Step 3. Verify that the pulse input circuitry on the module is
working correctly. Be sure the CCLK signal is present on
the rack's backplane if the rack contains more than one
module that can generate the CCLK signal. Check the
CCLK LED on the module's faceplate. The LED is on
when the CCLK signal is present on the backplane.
Remove power from the system. Disconnect the
mechanical coupling between the motor and the
pulsetach. Apply power to the rack and the pulsetach.
Use an oscilloscope on the terminal strip to verify that the
voltages coming from the pulsetach are at the proper
level.