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
The meaning of in- and outputs are configured via the
Master_Bus.pcl
file of this system. If changed
the busmaster transfers the (new) configuration to the nodes.
5.5.1 External local indication box
If external lamps should be used for signaling the actuator state, 2 lamps or LEDs could be connected
via X5. The lamp/LED connected to “Out1” is used for the “close” signal, “Out2” for the “open” signal.
Depending on the configuration (via busmaster) the lamps can signalize final positions only or a mov-
ing actuator, too.
5.5.2 External local control box
In some applications it is required to control a valve locally by means of two digital inputs and to indi-
cate the position by two outputs that may drive a LED. The above mentioned inputs and outputs can
be used for this purpose if the VCI is set to the applicable mode.
The behavior of the VCI card depends on the configured mode and button- or (key) switch-state.
•
Both inputs can be used in “normal” or “inverted” mode. Depending on the parameters they are
used active high (standard) or active low.
•
If
local buttons
are parametrized, pressing any button sets the actuator (the VCI-
card) in “local
mode” and the VCI handles the signal as immediate open or close command. Further drive com-
mands from the PLD or a SCADA system will be refused!
There are two possibilities to return to “remote mode” (standard):
1) There is a “local release command”, that can be send from the SCADA system or any PLD.
2) By pressing both buttons (open & close) simultaneously
for ~2 seconds. Returning to “remote
mode” by this way is signalized by illuminating both external feedback lamps for ~5 seconds.
•
If one or two
local key switches
are used and parametrized, the behavior is quite different:
The actuator will be in “local mode” as long as one key switch is active. All commands from SCADA
system and PLD(s) are refused, even the “local release command” won’t have an effect! Switching
the key switch(es) “off” again (no input active) returns to “remote mode” immediately!
CAUTION
Malfunction
If one(more) actuator(s) is(are) used in local mode, automatic functions like healing,
water treatment or something like that might be disturbed!
DANGER
Serious injuries
The local mode (especially with key switches) will hold the position open or closed to-
tally independent of the state of the SCADA system or the busmaster(s). That could be
important for service and maintenance.
But if it’s an e.g. spring close actuator and no bus power is available (switched off or
power failure) any not predetermined
position (e.g. “close” if spring close)
can’t be
held!
The valve
will close
for example!
5.5.3 Extended SCADA-Inputs and SCADA-Outputs
If no local control is needed, the In- and Outputs can be used independent from the actuator under
control of the SCADA-system.
•
The extended inputs can collect up to two digital or analog signals. These signals are read together
with the drive and error state by the busmaster and written into data registers that could be read by
the SCADA-system.
