# Modbus Protocol for .NET | Serial The Modbus Serial protocol implementation. ## Example A simple example which reads the voltage between L1 and N of a Janitza device. ```csharp string serialPort = "COM5"; using var client = new ModbusSerialClient(serialPort); await client.ConnectAsync(CancellationToken.None); byte unitId = 5; ushort startAddress = 19000; ushort count = 2; var registers = await client.ReadHoldingRegistersAsync(unitId, startAddress, count); float voltage = registers.GetSingle(); Console.WriteLine($"The voltage of device #{unitId} between L1 and N is: {voltage:N2}V"); ``` ## Sources - Protocol Specification: [v1.1b3] - Modbus Serial line: [v1.02] --- Published under MIT License (see [**tl;dr**Legal]) [v1.1b3]: https://modbus.org/docs/Modbus_Application_Protocol_V1_1b3.pdf [v1.02]: https://modbus.org/docs/Modbus_over_serial_line_V1_02.pdf [**tl;dr**Legal]: https://www.tldrlegal.com/license/mit-license