Rockwell Automation 1442 Eddy Current Probe System - Manual (Page 40)

40 Rockwell Automation Publication ICM-UM004C-EN-E - February 2014
Chapter 2 Maintenance and Inspection
Troubleshoot the Unit Use the table below to troubleshoot problems with the unit.
Symptom Possible Cause Recommended Action
Output is 0V DC and does not change. Power is not on. Turn on the power.
Unit is not connected properly. Refer to Connect the Wiring on page 32 to make sure the
unit is wired correctly.
The driver is faulty. Replace the driver.
Output is approximately -0.7V DC and does not change. The target is beyond the measurement range. Refer to Set Gap Voltage on page 36 to adjust the gap.
The sensor failed or the sensor cable is shorted or
disconnected. Measure the resistance between the sensor connector,
and if not normal, replace the sensor.
Normal value:
Sensor coil resistance: Approx. 5.5
Ω
Sensor cable resistance: Approx. 0.25
Ω/m
The extension cable is shorted or disconnected. Measure the resistance of the extension cable, and if it is
not normal, replace the extension cable.
Normal value:
Center conductor resistance: Approx. 0.25
Ω/m
Outer conductor resistance: 0
Ω
Center pin to outer conductor resistance: ∞Ω
There is a foreign object in the connector. Disconnect the connector, and remove foreign object in
the connector.
The driver is faulty. Replace the driver.
Output is approximately -22V DC and does not change. The target is outside the possible measurement range. Refer to Set Gap Voltage on page 36 to adjust the gap.
The driver is faulty. Replace the driver.