Siemens SIMATIC NET PROFIBUS - Manual (Page 38)

Topologies of SIMATIC NET PROFIBUS Networks
2-12
PROFIBUS Networks SIMATIC NET
6GK1970-5CA20-0AA1 Release 2 05/2000
Alternative Cabling Strategy
If the distance between two OLMs turns out to be too long, a structure as shown in
Figure 2-6 can be implemented.
OP 25
S7-400
PG
OP 25
ET 200M
PG/PC/OP
S7-400
PG
ET 200M
PG/PC/OP
1 FO cable
2 LAN cable for PROFIBUS
3 PROFIBUS 830-1T connecting cable
4 PROFIBUS 830-2 connecting cable
2 3 4 4 4
4
4
4
2 3
А
А А А
А
А А
А А
А
А А А А
А
А
А
А А
А
1
1 1 1 1
1 1 1
1
1
А Terminating resistor activated
1 1
Figure 2-6 Alternative Cabling of a Network Structure in an Optical Two-Fiber Ring Topology