PCL
Pleiger Elektronik GmbH & Co. KG
www.pleigerelektronik.de
Fon +49 2324 398 333
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Pleiger Control Loop
Manual version 2018-03
5
Valve Control Interface (PCL-VCI)
The data interface, the short circuit detection as well as the valve control
unit are implemented on a single PCB the PCL-VCI (Valve Control Inter-
face). This board may either be integrated in the drive’s case or may be
installed in a separate bus box.
5.1 Interface to actuator
Two relays, two binary inputs and one analogue 4..20mA input form the
interface to the valve drive. Additionally the board also supplies the limit
switches and eventually the analogue feedback unit of the drive. The sup-
ply voltage is 15..27V at 30mA maximum.
One of the two relays is always used as a make contact whereas the
second one can be switched to two different operational modes by means
of an additional solenoid valve supply switch (
S1
).
1. make contact switching the 230VAC of the power bus (standard)
2. break contact switching an external supply voltage of 230V AC (or
24V DC) (
S1
in position “quick close”)
Operation mode 1 is the standard one (& delivery status).
Mode 2 is used for single acting valves that must stay open in case of a
power fail or such valves that belong to a separately hard-wired quick
close system. If the external supply voltage is turned off the valve will
close in any case.
5.1.1 Quick Closing Operation
The PCL system uses two different ways to connect the drives to a quick closing system:
1. Software Control:
The quick close signal is collected by the busmaster by means of one or more digital inputs
(24V = normal operation, 0V = quick close). In case of a “quick close state” a close command
is sent to all nodes that belong to this quick close system. This of course requires that the data
transfer function of the system is working properly.
2. Hardware Control:
The quick close signal is hard wired to each drive of the quick close system. This wiring is
used to supply the magnetic valve within each single acting drive. If this supply voltage is
turned off, the drive will close regardless of the proper function of the data communication sys-
tem.
CAUTION
Malfunction / Material damage
Take care that the S1 switch is in
“standard” position if no external 24V DC or inde-
pendent 230V AC quick close supply is connected. If an external supply voltage is con-
nected to X2.10 & X2.11, the switch must be in “quick close” position!
A proper actuator configuration for the VCI-card is a mandatory requirement, too!
A wrong configuration or wrong switch setting can cause malfunctions or defective to
the PCL-VCI, the connected actuator or feedback modules!
Figure 5-1: PCL-VCI-card
3-3 (with extended in- &
outputs)
