Siemens Sinamics G120 CU240E Operating Instructions Manual page 151

A difference in the ground potential between the master and slaves in an RS 485 network
can damage the converter Control Unit. You must make absolutely sure that the master
and slaves have the same ground potential.
SUB D connection on the CU 240S (pin assignment)
The CU240S Control Units are equipped with a 9-pole SUB D socket for connecting the
inverter via an RS 485 interface. A standard 9-pole SUB D connector with a 180° cable outlet
can be used for the USS connection via RS 485.
Table 5- 48
Cable lengths and number of devices
Table 5- 49
Baud rate in bit/s
9600
19200
38400
57600
115200 (max. baud rate)
Frequency inverter
Operating Instructions, 08.10. 2008, t.b.d.
CAUTION
Contact assignment of the 9-pole SUB D socket
Con Description
tact
1 -
2 -
3 RS 485P
4 -
5 0 V
6 -
7 -
8 RS 485N
9 -
X Shield
(housing)
Max. no of devices and cable length
Description
Unused
Unused
Receive and transmit signal (+)
Unused
Ground reference
Unused
Unused
Receive and transmit signal (-)
Unused
Equipotential bonding
Max. no. of devices
32
32
32
32
30
5.11 Operation in fieldbus systems
Max. cable length
1200 m
1200 m
1200 m
1200 m
1000 m
Functions
151