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
6
Bus IO Unit (PCL-IO)
The PCL-IO is used to acquire
digital and analog data via the
PCL system. Additionally con-
trol commands can be sent to
the process by means of two
relays. The PCL-IO provides
the same bus interface like the
PCL-VCI. All safety features of
the PCL are also implemented.
The PCL-IO is encased into a
waterproof (up to IP68) casing.
Water tight cable fittings are
used for the complete cabling.
6.1 Analog / digital in-
puts
The PCL-IO provides 8 analog inputs with an input range of 0..20,4mA. The internal resistance of
each input is 100Ohm. The inputs are not isolated from one another and therefore only suited for float-
ing current sources like pressure or temperature sensors. The PCL-IO also provides 24VDC to supply
the sensors. Self-resetting fuses protect the inputs against overload due to short circuit in the sensor
cabling.
An 8-fold switch on the board is used to configure the input either as analog or digital. If an input is
used as digital input a 24V input signal is converted to a 4mA current. Please note that these input
must only be used for floating signal sources like liquid level switches, relays etc.
current input = switch position ON
digital input = switch position OFF
CAUTION
Malfunction / Damage
Take care that the DIP-Switches are o
nly in “ON”-Position, if the equivalent input is
used with an analog 4-
20mA signal! The delivery state is “OFF”!
6.2 Isolated digital inputs
Additionally each PCL-IO provides two opto-isolated inputs. Both inputs have common 0V.
6.3 Digital relay outputs
For control purposes each PCL-IO is equipped with two relay outputs. Both contacts of a normally
open relay are connected to separate terminals.
6.4 Technical data PCL-IO
Power supply AC
230V
20%, 45…65Hz
max. power loop current
16A
rms
current to detect a short circuit
<= 10 mA
Power consumption
max. 6W
Power supply for ext. sensors
24VDC
0,7V, max. 200mA
Max error of analog inputs
max. ±0,4% of full range
Trigger level of digital inputs
12V ±2V
Ambient temperature (casing)
-25°C ... 55°C
Figure 6-1: PCL-IO-card
