Siemens S7-400 Data Packets in the MPI Network, Recommendation for MPI Addresses, Components

Networking

Data Packets in the MPI Network

Observe the following feature in the MPI network:

Note

If you connect an additional CPU to the MPI network during operation, data may be lost.

Remedy:

1.Disconnect power from the nodes to be connected.

2.Connect the nodes to the MPI network.

3.Switch on the nodes.

Recommendation for MPI Addresses

Reserve MPI address “0” for a service programming device and “1” for a service OP, which will later be briefly connected to the MPI network as required. Thus you assign different MPI addresses to the programming devices / OPs incorporated in the MPI network.

Reserve MPI address “2” for a new CPU. You thus avoid the duplication of MPI addresses after a CPU with a default setting has been installed in the MPI network (for example, when replacing a CPU). Thus you assign an MPI address higher than “2” to all CPUs in the MPI network.

Recommendation for PROFIBUS-DP Addresses

Reserve PROFIBUS-DP address “0” for a service programming device, which will later be briefly connected to the PROFIBUS-DP network as required. Thus you assign other PROFIBUS-DP addresses to all the programming devices incorporated in the PROFIBUS-DP network.

Components

You connect the individual nodes via bus connectors and the PROFIBUS-DP bus cable. Remember to provide a bus connector with PG female port for nodes into which a programming device may be plugged if required.

Use RS 485 repeaters for the connection between segments and for extending the cable.

5-8	Automation System S7-400	Hardware and Installation
		A5E00850741-01