Siemens 6ES7134-4FB51-0AB0 Manual page 20

Connecting
5.1 Connecting measuring sensors
Abbreviations used
The meanings of the abbreviations in the figures below are as follows:
M +
M -
M
ANA
M
L +
U
CM
U
ISO
Isolated measuring sensors
The isolated measuring sensors are not connected to the local ground potential. They can be
floating. Depending on local conditions or interference, potential differences U
dynamic) can occur between the measuring lines M- of the input channels and the reference
point of the measuring circuit M
To ensure that the permitted value for U
interference, the following applies:
● For the 2 AI U analog input module: Connect M- with M
The following figure illustrates the connection of isolated measuring sensors to the floating
analog input modules.
5
①
②
③
④
⑤
20
Measuring line (positive)
Measuring line (negative)
Analog measuring circuit reference potential
Frame connection
Rated load voltage 24 VDC
Potential difference between inputs and reference potential of the measuring
circuit M
ANA
Potential difference between M
4
Logic
Backplane bus
Ground bus
Central grounding point
Isolated measuring sensors
and central grounding point
ANA
.
ANA
is not exceeded in environments with strong EMC
CM
1
3
2AI U HS analog electronic module (6ES7134-4FB51-0AB0)
CM
!
ANA
2
Manual, 04/2007, A5E01076015-01
(static or