Connecting
5.1 Connecting measuring sensors
2AI U ST analog electronic module (6ES7134-4FB01-0AB0)
20
Manual, 04/2007, A5E01076000-01
Abbreviations used
The meanings of the abbreviations in the figures below are as follows:
M+:
Measuring line (positive)
M-
Measuring line (negative)
M
ANA
Analog measuring circuit reference potential
M
Ground connection
L+
Rated load voltage 24 V DC
U
CM
Potential difference between inputs and reference potential of the measuring
circuit M
ANA
U
ISO
Potential difference between M
ANA
and central grounding point
Isolated measuring encoders
The isolated measuring encoders are not connected to the local ground potential. These can
be potential-free. Depending on local conditions or interference, potential differences U
CM
(static or dynamic) can occur between the measuring lines M- of the input channels and the
reference point of the measuring circuit M
ANA
.
To ensure that the permitted value for U
CM
is not exceeded in environments with strong EMC
interference, the following applies:
●
For the 2 AI U analog input module: Connect M- to M
ANA
!
The following schematic representation illustrates the connection of isolated measuring
encoders to the optically isolated analog input modules.
0
0
0
0
9
9
1
2
3
4
5
0
/
0
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8
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8
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①
Logic
②
Backplane bus
③
Ground bus
④
Central grounding point
⑤
Isolated measuring encoders
