PD4-E ModbusRTU Online Manual

Modbus RTU

Modbus references: www.modbus.org.

  • MODBUS APPLICATION PROTOCOL SPECIFICATION V1.1b3, Date: 26.04.2014, Version: 1.1b3
  • MODBUS over Serial Line Specification and Implementation Guide V1.02, Date: 20.12.2006, Version: 1.02

The controller can be controlled by means of Modbus RTU. The I/O data, with, e.g., the preconfigured drive values (see Process data objects (PDO)), can be handled with the standard Modbus function codes. To configure your own I/O data, however, function code 2Bh (CAN Encapsulation) must be supported by the master in order for the parameters to be read and written independent of the process image.

If the master does not support this function code, the I/O image can be configured and stored using Plug & Drive Studio. The master can then access the data using the standard Modbus function codes.


The "Two-Wire Modbus Interface" electrical interface is supported by the controller in accordance

with standard EIA/TIA-485 (RS-485).

Modbus Modicon notation with PLCs

Many PLCs use the Modicon addressing model. This notation is not used in the Modbus standard.

The following address notation is relevant for Nanotec controllers:

  • Input register 30001 - 39999 is mapped to Modbus telegram address 0 (0h) - 9998 (270Eh).
  • Holding register 40001 - 49999 is mapped to Modbus telegram address 0 (0h) - 9998 (270Eh).
Note: Where Modbus addresses are mentioned in the manual, it may be necessary to implement the register addresses in the PLC in accordance with Modicon notation.
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