4 Function description
3.6 Ambient conditions
Component
Connection/function
Terminal
Analog output
4 – 20 mA
0 – 10 V
Signal
3
5
Gnd
4
6
Pulse output
Signal
20
Gnd
21
Analog input
Background illumination
0 – 10 V
18
Gnd
19
Serial interface
RS 485
B
10
A
11
RS 232
TxD
7
RxD
8
Gnd
9
Power supply
Different power supply units are available as accessories
+24 V DC
1
Gnd
2
Tab. 3: Pin assignment
3.6 Ambient conditions
Parameter
Unit
Data/value
Storage temperature min. – max.
[°C]
-20 ... +80
Operating temperature min. – max.
[°C]
-20 ... +70
Humidity (relative humidity, non-condensing)
[%]
97
EMC emitted interference/immunity to interference
EN 61326
Vibration
o
EN 60068–2–47
o
EN 60068–2–64
Shock
EN 61373
Isolation min.
[V]
500
Degree of protection
IP 65
Tab. 4: Ambient conditions
3.7 Accessories
Notice
The technical data of the accessories are specified separately
4 Function description
4.1 Functional principle
4.1.1
Usage
The electronic unit is provided for usage with a KRAL flowmeter.
Flowmeters generate a specific number of pulses per flow volume unit - depending on the size and
working point. This device-specific characteristic is called the K-factor (unit: pulses/liter) and is spe-
cified on the calibration certificate.
The pulse signals of one flowmeter can be evaluated. A pulse input for pick up with the following func-
tions is available:
o
NPN
o
PNP
o
Namur
8
OIE 15en-GB Edition 2020-03
Operating instructions