Siemens SIMATIC NET PROFIBUS manual Configuring Electrical Networks with RS-485 Repeaters

Configuring Networks

3.1.4Configuring Electrical Networks with RS-485 Repeaters

RS-485 Repeater

To increase the number of nodes (>32) in a network or to extend the cable length between two nodes, segments can be connected together using RS-485 repeaters to form a network. Figure 3-1 illustrates how several segments can be connected together with repeaters to create a network.

The RS-485 repeaters support all transmission rates from 9.6 Kbps to 12 Mbps.

S7-300

À

OP 25

S7-300

ET200SÀ

À

S7-300

OP 25

PG

À

OP 25

À

À	OP 25
	ET200M

	RS-485
	repeater
À	À

À ET200M

	OP 25
À	À
À	ET200S

OP 25

ÀTerminating resistor activated

Figure 3-1 Layout of an Electrical PROFIBUS Network Using RS-485 Repeaters

PROFIBUS Networks SIMATIC NET	3-9
6GK1970-5CA20-0AA1 Release 2 05/2000