WEST POS-124-U-PFN Technical Documentation Manual page 44

FAULT
ENABLE is active, the
READY LED is flashing.
ENABLE is active; the
READY LED is on, the
system moves to an
end position.
ENABLE is active, the
READY LED is on, the
STATUS LED is not
flashing, the system
moves to the target po-
sition but doesn't reach
it (positioning error).
ENABLE is active, the
READY LED is on, and
the system oscillates on
the spot.
Speed too low
Speed too high
12
The stability criterion of the hydraulic axes must be taken into account.
Page 44 of 70
CAUSE / SOLUTION
The flashing READY LED signals that a fault is been detected by the module. The fault
could be:
• A broken cable or no signal at the input (PIN 14 or 13), if 4... 20 mA signals are pa-
rameterized.
• 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 localised directly via the monitor.
The control circuit polarity is incorrect. The polarity can be changed with the SIGNAL:U
command or by reversing the connections to PIN 15 and PIN 16 or
PIN 19 and PIN 20.
Serious positioning errors can result from incorrect parameterization or incorrect sys-
tem design.
• Is the cylinder position specified correctly?
• Are the deceleration distances correct (to start the system the deceleration dis-
tances should be set to approx. 20... 25 % of the cylinder position
• Is the valve a zero lapped control valve or a standard proportional valve?
In the case of a proportional valve, the valve overlap which may be present should
be compensated for with the MIN parameters. Typical values are to be found in the
valve data sheet.
The system is working and also actuating the valve.
Various potential problems could be:
• The parametrisation is not yet adjusted to the system (gain too high).
• There is severe interference on the power supply.
• Very long sensor cables (> 40 m) and sensor signal interference.
• The MIN setting to compensate the valve overlap is too high.
As a basic principle, the parametrisation of the sensor data and the controller settings
must be carried out first (before switching on). An incorrect demand is equivalent to in-
correct system design which then leads to incorrect operation. If the system oscillates,
the gain should first be reduced (longer deceleration distances for D:A and D:B) and in
the case of overlapped valves the MIN parameter should also be reduced.
The drive may be able to move to position but the speed is too low.
• Check the control signal to the valve.
•
Via the integrated oscilloscope (U variable).
•
Measure the signal to the valve with an external oscilloscope / voltmeter.
• If the control is within the range of ± 100% (± 10V), the fault must be sought in the
hydraulics.
• If the control signal is relatively low, the following points should be checked:
•
Is the internal/external speed signal limiting the speed?
•
Which setting has been specified for the deceleration distance in relation to the
POSITION?
The drive should move to position. The drive moves in and out too fast leading to un-
controlled behaviour. Reducing the speed (VMAX parameter) has very little or no ef-
fect.
• The hydraulic system is over-sized. The entire parameterization of the movement
cycle cannot be reproduced (overlap and deceleration distance settings)
POS-124-U
12
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24.01.2022