MODBUS Builder object is used to construct MODBUS request and response messages. This object exposes a number of helper methods (via IModbusBuilder interface) that should be called to parse passed arguments and build message's byte array. The resulting byte array may later be used in a call to ITerminalSession.send, ITcpSession.send or IUdpSession.send methods.
To create a MODBUS Builder object, call the IModbusManager.createBuilder method.