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5.3.2
Output3
The standard version of the Flow Transmitter can generate a pulse output signal at Out-
put3. A voltage supply is required for this pulse output signal.
The extended version of the Flow Transmitter can generate two different output signals at
Output3, a pulse output signal or an analogue current output signal. Voltage supplies are
required for both types of signals.
The pulse output signal from Output3 is symmetrical (50 - 50 % duty cycle), and the
frequency is continuously variable from 0-1000 Hz.
Electronic counters and PLC's are normally connected to the pulse output, Output3.
The pulse output in the transmitter consists of a voltage free electronic switch contact. There-
fore, it is necessary to equip the count pulse input on the counter/PLC with a pull-up resi-
stance, if the counter/PLC has no internal pull-up.
The pull-up resistance R1 should be chosen
so that the current I is approx. 5 mA when
the contact in the Flow Transmitter is
switched on.
5.3.3
Output3, current output
The current output signal is in the range from 4 - 20 mA. The current output may be taken to
a regulator for controlling the liquid flow.
The current output from Output3 works as a
variable resistance. It therefore requires an
external supply voltage, which can provide
min. 12 V at terminals 17 and 18 in the Flow
Transmitter plus the voltage drop across the
load and cable. The necessary supply voltage
must be calculated for max. current, 20 mA.
22/55
FLOW TRANSMITTER
Output 3
Current signal:
Flow Transmitter, PD 340
COUNTER/PLC
Supply +
R1
I
+
16
Count
-
17
Supply -
551 107 01
+
Min. 12 V
Max. 50 V
-
551 108 01
Manual
Supply +
GND
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