Block Diagram Of The Rs 485 Repeater - Siemens SIMATIC S7-300 Reference Manual

Block diagram of the RS 485 repeater

• Bus segment 1 and bus segment 2 are galvanically isolated from each other.
• Bus segment 2 and the PG/OP socket are galvanically isolated from each
other.
• Signals are amplified
– between bus segment 1 and bus segment 2
– between PG/OP socket and bus segment 2
Segment 1
Figure 7-3
Programmable Logic Controllers S7-300 Module Data
A5E00105505-03
A1
Logic
B1
A1
B1
PG/OP-
5V
socket
L+ (24 V)
M
A1
B1
5 V
M5 V
Block diagram of the RS 485 repeater
1M
5V
24V 24V
RS 485 Repeater
Segment 2
A2
B2
A2
B2
1M
L+ (24 V)
M
PE
M 5.2
7-7