Modbus/TCP server function

There is the possibility of external access to the WebHMI registers via the Modbus/TCP protocol. To do this, go to the menu 'Configuration -> Modbus/TCP server' . If you specify the Export option in the list for registers, this register can be accessed externally via the Modbus/TCP protocol, with the address entered in the 'ModBus/TCP Address.' Address format is a value from 0..65535 . In this case, it's not about the address of the Modbus data model (for example 40001-49999 for holding registers), but about the address in the message (PDU address).

• 'read' - use the function Modbus number 4, Input Register;
• 'entry' '- either' function number 6 '(Write Single) is used to write one word, or' 16 '(Write Multiple) to write multiple;

An interesting application is the connection of heterogeneous systems to each other when WebHMI devices are installed in different systems, allowing them to exchange data among themselves. In this case, for example, to read the register using the Modbus / TCP protocol from another WebHMI device, you need to use the address in the format IRxxxxx (where xxxxx is the address on the server).