Engee documentation

Modbus Support Blocks

It is recommended to familiarize yourself with the documentation before working with the library Working with Modbus TCP block library.

The library of Modbus protocol support blocks is designed to communicate a real-time application running on the RITM KPM with automated process control system devices using the Modbus protocol.

When using this library, the RITM KPM, on which the real-time application is running, acts as a Modbus network client. Simultaneous operation with 16 servers (slaves) of the Modbus network is supported.

The following Modbus protocol functions are supported:

  • 1 (0x01) — reading values from multiple flag registers (Read Coil Status);

  • 2 (0x02) — reading values from multiple discrete inputs (Read Discrete Inputs);

  • 3 (0x03) — reading values from multiple storage registers (Read Holding Registers);

  • 4 (0x04) — reading values from multiple input registers (Read Input Registers);

  • 5 (0x05) — recording the value of one flag (Force Single Coil);

  • 6 (0x06) — writing the value to one storage register (Preset Single Register);

  • 15 (0x0F) — writing values to multiple flag registers (Force Multiple Coils);

  • 16 (0x10) — writing values to multiple storage registers (Preset Multiple Registers).