Modbus TCP

The controller can be controlled by means of Modbus TCP. In this chapter, the function codes of the Modbus communication structure are described.

Modbus references: www.modbus.org.

• MODBUS APPLICATION PROTOCOL SPECIFICATION V1.1b3, Date: 26.04.2014, Version: 1.1b3
• MODBUS Messaging on TCP/IP Implementation Guide V1.0b, Date: 24.10.2006, Version: 1.0b

All messages are sent to port 502 of the controller via TCP; only one connection is supported. No CRC (as it is used with Modbus RTU) takes place.

The I/O data with any preconfigured drive values (see Process data objects (PDO)) can be sent with the standard Modbus function codes. To configure your own I/O data, however, function code 2Bh (CAN Encapsulation) must be supported by the Modbus 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.

Otherwise, configuration by means of Plug & Drive interface is possible (see document Function description Plug & Drive interface).