Troubleshooting - WEST PAM-198-P Technical Documentation Manual

6.2

Troubleshooting

Initial situation is an operable status of the device and existing communication between the module and the
WPC-300 program. Furthermore, the parameterization of the valve control has to be done with the assistance
of the valve data sheets.
The RC mode in monitor can be used to analyze faults.
CAUTION: If using the RC (Remote Control) mode, all safety aspects have to be checked solidly.
In this mode the module is actuated directly and the machine control has no influence on the
module.
FAULT
ENABLE is active, the
module does not re-
spond, and the READY
LED is off.
ENABLE is active, the
READY LED is flashing.
ENABLE is active; the
READY LED is active;
no current to the sole-
noid (no spool move-
ment).
ENABLE is active, the
READY LED is active
and the spool position is
instable.
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CAUSE / SOLUTION
Probably the power supply is disconnected or the ENABLE signal is not present.
If there is no power supply there is also no communication via our operating program.
If the connection to the WPC-300 exists, the power supply is also available. In this
case the availability of the ENABLE signal can be checked via the monitor.
The flashing READY LED indicates that a fault is detected by the module. The fault
could be:

Failure detection in case of current signals at input PIN 9/10 or 14/13.
Input signal below 3 mA.

A broken cable or incorrect wiring to the solenoids.

Internal data error.
With the WPC-300 operating program the failure can be localized directly via the
monitor.

No command value is available or the parameterization is incorrect. With the
WPC-tool you can check if a command value is available. If not, you should
check the wiring and/or the command set-point (in the PLC for example).

If the command input is correct, you have to check the signal adaption. In OL
mode the feed forward value has to be used.

If the current is set too low (parameter CURRENT/MAX), the output current and
the expected pressure/movement are too low.

Wrong configured position sensor. If the input-scaling is set to voltage (V) and
the sensor supplies a current signal (4... 20mA), the measured value is always
high. The output signal to the valve is therefore low.

The valve is controlled correctly (the output is going up to the nominal current).
In this case you may have a hydraulic problem or you are using free-wheeling-
diodes in the solenoid plug. Please remove the free-wheeling-diodes to allow a
correct current measurement.
In many cases you may have a hydraulic problem.
Electrical problems may be:

Bad parameterized closed loop controller.

Electrical noise at the wire of the power supply.

Very long solenoid wiring (maybe current controller has to be adapted).

Instable current control loop. The adjustments of the PWM-frequency and the
dither (frequency and amplitude) have to be checked carefully. Good experi-
ences are made with:
a. PWM-frequency = 2600 Hz (higher frequency), the dither has to be aligned
to the valve (amplitude and frequency).
PWM-frequency = 100... 400 Hz (lower frequency), the dither amplitude is
b.
set to 0 % (disabled).
PAM-198-P 05.06.2020