Siemens SIMATIC ET 200X - Connection of Current Sensors (Two-Wire Measuring Transducers) to Analog Inputs (EM with Order Number 6 ES7 144-1 GB41-0 XB0)

Technical Specifications
7-107
ET 200X Distributed I/O Device
EWA 4NEB 780601602-06
Connecting current sensors as two- and four-wire measuring transducers
The supply voltage is fed to the two-wire measuring transducer and is inherently
short circuit-proof. The two-wire measuring transducer then converts the fed
measured value into a current. Four-wire measuring transducers have a separate
supply voltage connection.
The two-wire measuring transducers must be insulated measuring sensors.
The figure below shows how current sensors are connected as two-wire measuring
transducers to an EM 144 AI 2  I expansion module (4 to 20 mA).
M+
Two-wire
measuring
transducer
P
+
–
Sensor,
e.g. pressure gauge
M–
Socket X1
Socket X2
* Made available by the ET 200X for the connected sensor
Connection of socket X2:
see socket X1
1M
1L+*
1
2
3
4
1
2
3
4
Figure 7-25 Connection of current sensors (two-wire measuring transducers) to analog inputs (EM with
order number 6ES7 144-1GB41-0XB0)