#306 - How to transfer data from a Schneider PLC to a Siemens PLC through Modbus TCP

- Schneider's M580 CPUs have Modbus TCP enabled by default.

- On Control Expert, assign the variable a memory address (e.g., IO_INT, data type INT, memory address %MW10).

- On TIA Portal use the block MB_CLIENT to communicate via PROFINET as Modbus TCP Client.

- Parameters to configure in this block:

TCP:

> MB_MODE: 0 (Read)

> MB_DATA_ADDR: 40001 (Read Holding Register)

> MB_DATA_LEN: 125 (max)

> Connect: IPv4 address (note that it is in hexadecimal format, e.g., 16#C0 is 192), Modbus Port 502, HW identifier (from hardware system constants Local~PROFINET_interface_1), id (unique identifier for each MB_CLIENT instance), Connection Type (TCP/IP 16#0B is 11).

- The write is very similar, the few differences are the unique id, and the mode write (1) instead of read (0). Ensure the Modbus address exists in the master PLC (e.g., %MW500 for the memory address 40501).