Siemens Simatic S7-300 CPU 31xC Series User Manual

Wiring
6.9 Wiring the MPI / PROFIBUS DP bus connectors
S7-300, CPU 31xC and CPU 31x: Installation
6-16 Operating Instructions, Edition 08/2004, A5E00105492-05
Note
Use a bus connector with 90° cable exit.
See also
Network components of MPI/DP and cable lengths (Page 4-35)
6.9.2 Setting the terminating resistor on the bus connector
Bus connector: Plugging it into module
1. Plug the wired bus connector into the module.
2. Screw-tighten the bus connector on the module.
3. If the bus connector is located at the beginning or end of a segment, you must enable the
terminating resistor (switch setting "ON"; see the following figure).
Note
6ES7 972-0BA30-0XA0 bus connectors are not equipped with a terminating resistor. You
cannot insert this type of bus connector at the beginning or end of a segment.
Please make sure during startup and normal operation that power is always supplied to
nodes where the terminating resistor is active.

Siemens Simatic S7-300 CPU 31xC Series Specifications

General

Series	S7-300 CPU 31xC
Power Supply	24 V DC
Communication Interfaces	MPI, PROFIBUS DP
Programming Languages	LAD, STL, FBD, SCL
Operating Temperature	0°C to +60°C
Memory	48 KB - 512 KB
Dimensions	40 x 125 x 130 mm (varies by model)