Temperature Controller

Treat holding register 0 as oven temperature. Build against a virtual slave first, then replace the channel with a serial port on site.

var memory = new ModbusSlaveMemory();
memory.HoldingRegisters[0] = 1800; // raw value, scaled by 0.1 to 180.0

await using var app = ZeusHost.Create(builder =>
{
    builder.AddAcquisition(TimeSpan.FromMilliseconds(500));
    builder.AddVirtualChannel("bus", new ModbusSlaveResponder(1, ModbusTransport.Rtu, memory));
    builder.AddModbusRtu("oven", "bus", points: map =>
        map.HoldingRegister("temperature", 0, 0.1)
           .HoldingRegister("setpoint", 1, 0.1).Writable("setpoint"));
});

await app.StartAsync();
var pv = app.Points.Get<double>("temperature");
await app.Points.WriteAsync("setpoint", 180.0);

Replace the field channel later:

builder.AddSerialPort("bus", "COM3", 9600);
builder.AddModbusRtu("oven", "bus", unitId: 1);

The UI can display the temperature with app.Points.BindTo("temperature", label) and write the setpoint with WriteAsync("setpoint", 180.0). Protocol and UI code do not need to change when the channel changes.