Siemens LOGO! Series Manual page 418

Mounting and connecting
3.3 Connecting the HMI device
Configuring an RS422/RS485 port
A DIP switch for the configuration of the RS422/RS485 interface is located on the back of the
HMI device.
The DIP switch is set at the factory to enable communication with the SIMATIC PLC via
RS 485.
Note
Note the diagrams of DIP switch settings on the rear panel of the HMI device.
The following table shows the DIP switch settings. The send and receive direction is toggled
internally using the RTS signal.
Communication
DP/MPI/PPI
RS 422/RS 485
46
Switch setting Meaning
No RTS signal on connector, for data exchange between
the SIMATIC PLC and the HMI device
(factory state)
RTS signal on pin 4, same as PLC,
for example, for commissioning
RTS signal on pin 9, same as for a programming device,
for example, for commissioning
RS 422/RS 485 interface is active, for example, for
connecting PLCs of other manufacturers
Operating Instructions, 04/2012, A5E02421799-03
Basic Panels