IP based Protocols

The library provides several flavours of IP based Modbus protocols.

The MODBUS/TCP master protocol is implemented in the class MbusTcpMasterProtocol and is the only IP based protocol officially specified by the Modbus organisation.

In addition to MODBUS/TCP, the library offers implementations of both serial protocols RTU and ASCII transported over TCP streams. These are implemented in the classes MbusRtuOverTcpMasterProtocol and MbusAsciiOverTcpMasterProtocol.

Also an implementation for MODBUS/TCP packets transported via UDP is available in form of the class MbusUdpMasterProtocol.

All classes provide functions to establish and to close a TCP/IP connection to the slave as well as data and control functions which can be used after a connection to a slave device has been established successfully. For a more detailed description of the data and control functions see section Data and Control Functions for all Modbus Protocol Flavours.

Using multiple instances of a MbusTcpMasterProtocol class enables concurrent protocol transfers using multiple TCP/IP sessions. They should be executed in separate threads.

See section The MODBUS/TCP Protocol for some background information about MODBUS/TCP.