Connecting; Connecting Measuring Sensors - Siemens 6ES7134-4FB51-0AB0 Manual

Connecting

5.1

Connecting measuring sensors

Introduction
You can connect encoders with voltage signals to the 2AI U HS analog input module.
In this chapter you will find out how to connect the measuring sensors and what to watch for
when doing so.
Lines for analog signals
You should use shielded and twisted-pair lines for the analog signals. This reduces the effect
of interference. You should ground the shield of the analog lines at both ends of the line. If
there are differences in potential between the ends of the line, a compensating current flows
via the shield that can interfere with the analog signals. If this is the case, you should only
ground the shield at one end of the line.
Analog input modules
In the case of the analog input modules there is electrical isolation:
● Between logic and backplane bus
● Between load voltage and the channels The following are used:
Connection of measuring sensors to analog inputs
Between the measuring lines M- of the input channels and the reference point of the
measuring circuit M
voltage). To ensure that the permitted value is not exceeded, you must take different steps
depending on the whether the sensors are isolated or non-isolated. The steps you have to
take are described in this chapter.
2AI U HS analog electronic module (6ES7134-4FB51-0AB0)
Manual, 04/2007, A5E01076015-01
– Isolation: No link between M
Note
Ensure that this potential difference U
is a possibility of exceeding the permitted value, make a connection between terminal
M and the central grounding point.
ANA
there can be only a limited potential difference U
ANA
and the central grounding point (U
ANA
does not exceed the permitted value. If there
ISO
5
)
ISO
(common-mode
CM
19