CODESYS Modbus TCP Client SL

The CODESYS Modbus TCP Master configurator, which is integrated in the CODESYS Development System, expects a license on the device. This license is either already stored in the controller by the device manufacturer or added afterwards by the end user. The product is also available for Modbus Master (RTU).

This license is already included in SoftPLC systems from 3S-Smart Software Solutions (example: CODESYS Control Win or CODESYS Control for Raspberry Pi). The license is saved to a CODESYS compatible device — on CODESYS Key (hardware device) or Soft Key (software license container).If a license for the CODESYS Modbus TCP Master is available on the device to be programmed, then the device can communicate with connected adapters and read and write their inputs and outputs, respectively. For this purpose, the communication parameters are predefined in the configurator, for example the settings of the Ethernet adapter (baud rate, port number).

Modbus commands are defined in the configurator and are oriented to a specific Modbus slave. The commands are processed by the device at specific intervals, or triggered programmatically. For predefined commands, I/O channels are generated automatically with variables that can be mapped (I/O mapping).

Processing requires a protocol stack and CODESYS I/O driver that implements Modbus communication on the configured Ethernet port. This I/O driver is supplied with the license as CODESYS libraries.