Modbus

Library provides modbus wrapper over RTU and TCP connections. Using serialport for RTU.

Simple usage:

auto mbus = new ModbusRTUMaster("/dev/ttyUSB0", 19200);
mbus.readTimeout = 2.seconds;
writeln(mbus.readInputRegisters(1, 17, 1));

Implemented functions:

• 01 (0x01) readCoils
• 02 (0x02) readDiscreteInputs
• 03 (0x03) readHoldingRegisters (returns const(ushort)[] in native endian)
• 04 (0x04) readInputRegisters (return in native endian too)
• 05 (0x05) writeSingleCoil
• 06 (0x06) writeSingleRegister
• 16 (0x10) writeMultipleRegisters

If you need other function you can use it directly:

auto res = mbus.request(dev, fnc, expectedDataLength, args);

where args is compile time variadic arguments, they convert to big endian by element for sending inside lib. res returns in big endian and you must convert to little endian by yourself.

And if you can test new function welcome to pull requests =)

For tcp connection using std.socket.TcpSocket.

auto addr = "device_IP";
ushort port = 502; // or 503
auto mbs = new ModbusTCPMaster(new InternetAddress(addr, port));
writeln(mbs.readInputRegisters(1, 17, 1));

ModbusRTUMaster and ModbusTCPMaster close serial port and socket in destructors.