PLC Multi-Point Interface (MPI) and the global data set PLC Programming

a, multi-point interface (MPI)
S7-300 / S7-400 PLC via the MPI interface can be composed of a network, MPI network using global data (Globe Data) communication mode, can be a small amount of data exchange between the PLC. It requires no additional hardware and software, low cost, simple usage.MPI network is used to connect a number of different CPU or equipment. MPI compliance with RS-485 standard, the nature of multi-point communications. MPI baud rate is set to 187.5kbps.
b, multipoint interface (MPI) global data set
GD communication data structureGD communication applications

1. Establish MPI station hardware configuration 12. Setting the MPI Station address 13. Establish MPI station hardware configuration 2, open configuration interface CPU feature set MPI Station address 24. Click Configure Network into the configuration web interface5. Opening a global data table Options / Define Global Date6. Global data generation and load, CPU to CPU communication realizationSend / receive data rules: a station transmitting data MPI MPI can be sent to multiple stations, a data receiving MPI stations can receive the transmission data a MPI stations.Control program SIMATIC S7300 (1) station and SIMATIC S7300 (2) Station