Configuring   
4.11 Planning subnets 
  S7-300, CPU 31xC and CPU 31x: Installation 
4-38  Operating Instructions, Edition 08/2004, A5E00105492-05 
Installation of bus cables 
When you install PROFIBUS cables, you must not 
•  twist, 
•  stretch 
•  or compress them. 
When wiring indoor bus cables, also maintain the following marginal conditions (d
A
 = outer 
cable diameter): 
Table 4-23  Marginal conditions for wiring interior bus cables 
Characteristics  Condition 
Bending radius (one-off)  ≥ 80 mm (10 x d
A
) 
Bending radius (multiple times)  ≥ 160 mm (20 x d
A
) 
Permitted temperature range during installation  –5 °C to +50 °C 
Shelf and static operating temperature range  –22 °F to +149 °F 
Reference 
For information on the use of fiber-optic cables for PROFIBUS, refer to the SIMATIC NET, 
PROFIBUS Networks Manual. 
Bus connector RS 485 
Table 4-24  Bus connector 
Type  Order number 
RS485 bus connector, up to 12 Mbps,  
with 90° cable exit,  
without PG interface,  
with PG interface 
 
 
 6ES7 972-0BA11-0XA0 
 6ES7 972-0BB11-0XA0 
Fast Connect RS485 bus connector, up to 12 Mbps,  
with 90° cable exit, with insulation displacement technology, 
without PG interface,  
with PG interface 
 
 
 6ES7 972-0BA50-0XA0 
 6ES7 972-0BB50-0XA0 
RS485 bus connector up to 12 Mbps  
with 35° cable exit (not for CPU 31xC, 312, 314, and 315-2 DP 
without PG interface 
with PG interface 
 
 
6ES7 972-0BA40-0XA0 
6ES7 972-0BB40-0XA0 
Fields of application 
You need bus connectors to connect the PROFIBUS cable to an MPI or PROFIBUS-DP 
interface 
You do not require a bus connector for: 
•  DP slaves with degree of protection IP 65 (ET 200X, for example) 
•  RS 485 repeater.