Siemens SIMATIC NET PROFIBUS manual Block Diagram of the RS-485 Repeater

Active Components for RS-485 Networks

Block Diagram

Figure 5-1 shows the block diagram of the RS-485 repeater:

SBus segment 1 and bus segment 2 are electrically isolated.

SBus segment 2 and the PG/OP connector are electrically isolated.

SSignals are amplified:

–between bus segment 1 and bus segment 2

–between the PG/OP connector and bus segment 2

Segment 1 A1 B1 A1 B1

PG/OP socket L+ (24 V)

M

A1

B1

5 V

M5 V

	Segment 2
Logic	A2
	B2
	A2
	B2

5V	1M 5V	1M
24 V	24 V	L+ (24 V)
		M

PE

M 5.2

Figure 5-1 Block Diagram of the RS-485 Repeater

PROFIBUS Networks SIMATIC NET	5-5
6GK1970-5CA20-0AA1 Release 2 05/2000