Troubleshooting - W.E.ST. MDR-133-U Technical Documentation Manual

6.2 Troubleshooting

It is assumed that the device is in an operable state and there is communication between the module and the
WPC-300. Furthermore, the valve control parameterization has been set with the assistance of the valve data
sheets.
The RC mode in monitor window can be used to analyze faults.
CAUTION: All safety aspects must be thoroughly checked when working with the RC (Remote
Control) mode. In this mode the module is controlled directly and the machine control cannot
influence the module.
FAULT
ENABLE is active, the
module does not
respond 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 solenoid (no
pressure-build-up).
ENABLE and START are
active, the READY LED is
active, and the pressure
control loop works, but
there are high errors
mainly at lower or higher
command pressure.
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CAUSE / SOLUTION
There is presumably no power supply or the ENABLE signal (PIN 8) is not present.
If there is no power supply, there is also no communication via our operating
program. If a connection has been made to the WPC-300, then a power supply is
also available.
If the power supply exists, an attempt should be made to see whether the system
can be moved by means of the HAND+ and HAND- inputs (measuring the output
signal to the valve helps).
The flashing READY LED signals that a fault has been detected by the module. The
fault could be:

A broken cable or no signal at the input (PIN 13 or PIN 14), if 4... 20 mA signals
are parameterized.

A broken cable or incorrect cabling to the solenoids (in the P version only).

Internal data error: press the command/SAVE button to delete the data error. The
system reloads the DEFAULT data.
With the WPC-300 operating program the fault can be localized directly via the
monitor.
To locate errors in the pressure-control-circuit, it is useful to start with the open loop
pressure control (PIN 7 is not activated). In this case the module works like a power
amplifier.

No pressure command input is available or the parameterization is incorrect.
With the WPC-tool you can check if a command input 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 valve control parameter.
If the current is set too low (parameter CURRENT), the output current and the
expected pressure are too low.

Wrong configured pressure sensor (if PIN 7 is active). If the input-scaling is set
to voltage (V) and the pressure sensor supplies a current signal (4... 20mA), the
measured pressure value is always high. The output signal to the valve is there-
fore low. For further checking: disable PIN 6.

The pressure 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.
The non linearity of the valve is higher than the controlling range of the integrator.
The parameter LIM:I should be increased.
MDR-133-*-2030 29.08.2019