Siemens 6ES7134-4GB11-0AB0 - Page 21

Connecting
5.1 Connecting measuring sensors
2AI I 4WIRE ST analog electronic module (6ES7134-4GB11-0AB0)
Manual, 04/2007, A5E01076100-01
21
Non-isolated measuring encoders
The non-isolated measuring encoders are connected to the local ground potential. You must
connect M
ANA
to the ground potential. Depending on local conditions or interference,
potential differences U
CM
(static or dynamic) can occur between the locally distributed
measuring points.
If the permitted value for U
CM
is exceeded, there must be equipotential bonding conductors
between the measuring points.
The following schematic representation illustrates the connection of non-isolated measuring
encoders to an optically isolated analog input module.
Connection of non-isolated measuring encoders to an optically isolated analog input module:
1
2
3
4
5
0
0
/
0
0
0
$'8
8
,62
P$
P$
8
&0
0
$1$
① Logic
② Backplane bus
③ Ground bus
④ Equipotential bonding conductor
⑤ Non-isolated measuring encoders
Operating four-wire transmitters on an external voltage supply
If there is electrical isolation between the output and the transmitter supply, you can connect
the transmitter to the 2 AI I 4WIRE ST without the need for additional connections.
If there is no electrical isolation between the output and the transmitter supply, you can only
connect the transmitter to the 2 AI I 4WIRE ST if the reference potential of the supply
voltages (24 V DC) is the same.
If there is an increase in interference radiation, it is recommended that you connect M- to
M
ANA
on the terminal module of the 2 AI I 4WIRE ST.