Rs232; Preparing The Inverter For Remote Control Operation - Siemens 6SE2101–1AA01 Operating Manual

7.2.2 RS232

It is possible to use an RS232 interface for installations where the distance between the master computer and the
inverters is less than 5 m and the amount of electrical interference generated by adjacent equipment is low.
For the connection method shown in Figure 9 below to operate satisfactorily, it is essential that there is no
connection between the 0V reference of the inverter (X11.1, X11.8, X11.10 or X11.22) and the ground reference for
the master computer.
Figure 9: RS232 Connections

7.3 Preparing the Inverter for Remote Control Operation

The inverter must be manually set into remote control mode before the remote control facility can be used. This is
achieved by programming configuration parameters P20, P21 and P22 (see section 5.3.2) .
Parameter P20 selects manual/remote control and simple or USS protocol
When under manual control, the inverter will reply to query messages received over the serial link, but will
ignore commands to change its operational status. In remote control mode, all control is via the serial link.
All manual controls are ignored, except for the ability to switch back to manual mode by changing P20.
P20 = 000 Monitor mode, simple protocol
= 001 Control / Monitor mode, simple protocol
= 002 Monitor mode, USS protocol
= 003 Control / Monitor mode, USS protocol
Parameter P21 selects the device number (0 to 30)
Each inverter connected to the serial line must be allocated a unique device number. This is used to
identify which inverter the remote device wishes to talk to. Each inverter will only respond to commands
destined for that inverter.
P21 = appropriate address (000 to 030)
Parameter P22 selects the serial baud rate and parity
The inverter will operate at 2400, 4800 or 9600 baud with even, odd or parity ignored.
P22 = 000 2400 baud
= 001 4800 baud
= 002 9600 baud
= 003 2400 baud
= 004 4800 baud
= 005 9600 baud
= 006 2400 baud
= 007 4800 baud
= 008 9600 baud
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INVERTER
Ω
100
A
RS232 X11
TX
RX
GND
TX = Pin 2
RX = Pin 3
GND = Pin 5 (Pin 7 for 25–way D–type connector)
even parity
even parity
even parity
odd parity
odd parity
odd parity
ignore
ignore
ignore
INVERTER
B A B
X11
English
A = X11.14
B = X11.15