VAT 64246-UEHC-0001, Installation, Operating, & Maintenance Instructions

Page: 46 / 73

OPERATION
Series 642
46/73 Edition 2013-08-22 603685EA
5.6.2 Operation
Description / Mode Digit 1 Digit 2 Digit 3 Digit 4
PRESSURE CONTROL mode P
0 . . . 100
= valve position (%, 0 = closed / 100 = open)
POSITION CONTROL mode V
Valve closed C
Valve open O
HOLD (position frozen) activated H
ZERO running Z
LEARN running L
Safety mode established. Refer
to «Safety mode» for details.
D
Service request
1)
S R
Power failure F
1)
SR is blinking alternatively with the actual mode display (e.g. C

SR)
5.6.3 Errors
Description Digit 1 Digit 2 Digit 3 Digit 4
Fatal error occurred E Error code. Refer to «Trouble shooting» for details
5.6.4 Safety mode
By means of an external switch (see connection diagrams «Electrical connection») the motor power
supply can be interrupted. In this case the valve enters the ‘safety mode’. This motor interlock prevents
the valve from moving (e.g. maintenance work). Data reading from the control unit remains possible.
When motor interlock is active during power up the valve directly enters the ‘safety mode’ and is not able
to synchronize. Display shows ‘D C’ or ‘D999’. In this case synchronization cycle will be done when
motor interlock is deactivated. Then
Display shows ‘INIT’ for a moment followed by ‘SYNC’.
When ‘safety mode’ is entered from operation (i.e. pressure control mode), the unit will automatically
switch to position control mode and remain at current position. Once motor interlock is deactivated the
unit remains in position control mode.
5.6.5 Service indication
This product is able to indicate that the valve unit needs to be cleaned, or an obstruction is present.
A service request is indicated when the control unit detects that motor steps are apparently not effective.
This may happen when the valve unit is heavily contaminated. These ‚lost‘ steps are recognized and will
be repeated to attempt target position in the short term. But in the medium term the valve unit requires
cleaning or inspection.
‘Service request’ (SR) would be indicated on the display or could be read via
remote operation. Refer to «Display information» for details.