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Installation and connection
4.3 Connecting the HMI device
TP 270, OP 270, MP 270B (WinCC flexible)
4-14
Operating Instructions, Edition 03/2004, 6AV6691-1DD01-0AB0
Configure interface IF1B
The IF1B interface can be configured via the switch on the back of the HMI device. This
switches over the RS-422 received data and the RTS signal for RS485.
By default, the switch is set for the SIMATIC S7 PLC.
The following table shows the permissible switch settings.
Communication Switch
settings
PLC
MPI/PPI
Standard cable
Operating
unit
ON
1
2
3
4
No RTS on connector
This is the switch setting on
delivery.
PLC
RS 422/RS 485
Operating
unit
ON
1
2
3
4
ON
1
2
3
4
RTS on Pin 4 (default)
ON
1
2
3
4
RTS on Pin 9 (as PU)
PLC
PROFIBUS-DP/MPI
Operating
unit
ON
1
2
3
4
No RTS on connector