Hyd-Mech H18A-120, Manual

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3.12
Problem #4
No Display
Possible Causes:
1. No power to the HMI.
2. PLC unit failure.
3. Faulty connection of cable between PLC and Interface.
4. Faulty HMI unit.
Diagnosis:
a. Check the power LED. This light should be on when the PLC is switched on.
b. If the light is on, the PLC may have failed. Check for proper connection of the cable at the PLC and at the inter
face. Also check the PLC fuse.
c. If the fuse is OK, ensure that power is being supplied to the fuse.
Problem #5
No blade speed display
Possible Causes:
1. Faulty proximity sensor
2. Misadjusted sensor (the gap should be approx .030” - .040”)
3. Contamination on the end of the sensor.
4. Faulty PLC unit.
5. Bad connection of sensor wiring
Diagnosis:
• Check for the LED light on the sensor. The light indicates that the sensor has power and is activated. The problem
could be with the sensor, signal wire to the PLC or with the PLC itself. With the blade running, the light on the back of the
sensor should “pulse”. Likewise, the PLC input LED X2, should also be “Pulsing”. If both LED’s are pulsing with the blade
running, the PLC is the problem. If the sensor is pulsing but the input LED on the PLC is not, there is a problem between
the sensor and the PLC unit.
• If the LED on the sensor is not on, the problem is with the sensor wiring or the sensor is at fault.
M12 PIN ASSIGNMENTS FOR I/P & O/P DEVICES