Siemens SIMATIC ET 200AL - Page 1423

Connecting transducers
4.1 Overview
Analog value processing
66 Function Manual, 06/2014, A5E03461439-AC
Abbreviations used in the figures
Key to the abbreviations in the figures below:
AI
Analog input module
M
Ground connection
L+
Supply voltage connection
M
n
+/M
n
-
Measuring input, channel n
I
Cn
+/I
Cn
-
Current output to thermal resistor (RTD) channel n
U
n
+/U
n
-
Voltage input channel n
I
n
+/I
n
-
Current input channel n
COMP+/COMP-
Compensation input
I
Comp
+/I
Comp
-
Current output for compensation
U
V
Feed voltage at channel (the connection can be used for 2
-wire
transducer (2DMU) or with ET
200eco PN and ET 200pro for 2/4-wire
transducer).
U
CM
Potential difference between the reference points of the measuring
inputs / the analog ground M
ANA
U
ISO
Potential difference between the reference points of the measuring
inputs and the central ground
M
ANA
Reference point of the analog ground
Lines for analog signals
Always use shielded twisted-pair cables to wire the analog signals. This improves immunity.