Connecting Loads/Actuators To Analog Outputs - Siemens SIMATIC S7-400 Reference Manual

5.14

Connecting loads/actuators to analog outputs

Introduction
The analog output modules can be used to supply power to loads and actuators.
This section contains general information that is generally applicable to all the connection
options for loads and actuators described in the sections that follow.
Cables for analog signals
Always use shielded twisted-pair cables to wire analog signals. Form two twisted pairs of the
Q and S+, and M and S- signals. This reduces interference. Connect both ends of the analog
V
cable shield to ground.
If there are potential differences between the cable ends, an equipotential bonding current,
which can flow over the shield, can cause interference of the analog signals. To avoid this
situation, you should ground the shield only at one end of the cable.
Isolated analog output modules
With the isolated analog output modules there is no electrical connection between the
reference point of the measuring circuit M
You must use isolated analog output modules if a potential difference U
the reference point of the measuring circuit M
equipotential bonding conductor between the M
that U
S7-400 Automation System Module Data
Reference Manual, Ausgabe 11/2016, A5E00850736-08
does not exceed the permitted value.
ISO
5.14 Connecting loads/actuators to analog outputs
and chassis ground.
ANA
and chassis ground. By means of an
ANA
terminal and chassis ground, make sure
ANA
Analog modules
can occur between
ISO
219