Modbus TCP configuration
Modbus is one of the most widely used communication protocols in automation technology.
It enables standardized data exchange between controllers, measuring devices, drives, and higher-level systems—regardless of the manufacturer. Thanks to its simple structure, Modbus is easy to understand, quick to implement, and suitable for many applications.
The Modbus register assignments determine which data is stored at which address in a device.
The DEDITEC Modbus registers always start at 0 (base = 0).
General register allocation
| Modbus register (dez) |
Data type | Access | Data size (Bit) |
Description |
| 0 ... 9999 | Coil | write / read | 1 | Writing and reading back digital outputs |
| 10000 ... 19999 | Discrete Inputs | read | 1 | Read digital inputs |
| 30000 ... 39999 | Input Register | read | 16 | Read holder register |
| 40000 ... 49999 | Holding Register | write / read | 16 | Write and read back registers |
With the correct register assignment, you know exactly where which information is stored in the device and can read, monitor, or change it in a targeted manner.