Siemens D7-SYS - Page 229

Communications configuring
3-140 System- and communication configuring D7-SYS - SIMADYN D
Edition 12.2003
390
Ω
150
Ω
RS485+
22
390
Ω
RS485-.
18
21
17
5
8
7
14
2
20
USS busSS4
Fig. 3-46 Connector assignment with basis network
This circuit should be used if the SS4 communications module is not
used as end node on the USS bus, i. e. not at the end of the bus cable. In
this case, the bus cable is looped-through the bus connector.
RS485+
RS485-
21
17
5
8
7
14
2
20
USS busSS4
Fig. 3-47 Connector assignment without basis network
Connector
assignment
without basis
network