The CP 342-5 FO is the communications processor of the SIMATIC S7-300 for the PROFIBUS DP optical bus system.

The CP 342-5 FO has a fiber optic interface that facilitates interference-immune connections even in environments with severe levels of radio interference.

It relieves the CPU of communications tasks.

Communication of the SIMATIC S7-300 with:

• the distributed I/O system ET 200 with integral optical interface
• SIMATIC S7-400 with IM 467 FO and CP 342-5 FO
• PC with CP 5613 FO
• Remaining PROFIBUS nodes via the optical bus terminal (OBT)

The number of CPs that can be used is dependent on the performance range of the CPU and on the communications services used.