Building a Modbus config programmatically (no JSON file)

"""Example: Building a Modbus config programmatically (no JSON file).

Constructs a ModbusConfig in Python and passes it directly to ModbusDevice.
Useful when configs are generated dynamically or assembled from multiple sources.

Start the sim server first:
    python -m instro.modbus.sim_server

Then run this script.
"""

import time

from instro.modbus import (
    DeviceInfo,
    LinearScale,
    ModbusConfig,
    ModbusDevice,
    RegisterDef,
    TCPConnection,
    TimingConfig,
)

config = ModbusConfig(
    device=DeviceInfo(
        name="sim_device",
        description="Programmatically configured simulated device",
        manufacturer="Sim Corp",
        model="SIM-3000",
    ),
    connection=TCPConnection(host="127.0.0.1", port=5020, unit_id=1, timeout=2.0),
    timing=TimingConfig(poll_interval=0.5),
    registers=[
        RegisterDef(
            name="temperature",
            starting_address=0,
            register_type="holding",
            data_type="float32",
            write_min=0.0,
            write_max=500.0,
        ),
        RegisterDef(
            name="pressure",
            starting_address=2,
            register_type="input",
            data_type="float32",
            read_group="sensors",
        ),
        RegisterDef(
            name="flow_rate",
            starting_address=4,
            register_type="input",
            data_type="float32",
            read_group="sensors",
        ),
        RegisterDef(
            name="scaled_count",
            starting_address=16,
            register_type="input",
            data_type="uint32",
            scale=LinearScale(gain=0.001, offset=0),
        ),
        RegisterDef(
            name="mode",
            starting_address=4096,
            register_type="holding",
            data_type="uint16",
            write_value_map={"off": 0, "standby": 1, "run": 2},
            write_min=0,
            write_max=2,
        ),
        RegisterDef(
            name="enable",
            starting_address=0,
            register_type="coil",
        ),
    ],
)


def main():
    device = ModbusDevice(config, autostart=True)

    try:
        print(f"Connected to {config.device.name}")
        print(
            f"Polling {len([r for r in config.registers if r.poll])} registers every {config.timing.poll_interval}s\n"
        )

        # Read sensors
        print(f"temperature: {device.read('temperature')}")
        print(f"pressure:    {device.read('pressure')}")
        print(f"scaled_count: {device.read('scaled_count')}")

        # Write using value_map
        device.write("mode", "run")
        print(f"\nWrote mode='run' -> read back: {device.read('mode')}")

        # Write with fat-finger protection
        device.write("temperature", 75.5)
        print(f"Wrote temperature=75.5 -> read back: {device.read('temperature')}")

        try:
            device.write("temperature", 999.0)
        except ValueError as e:
            print(f"\nFat-finger protection: {e}")

        # Toggle coil
        device.write("enable", True)
        print(f"\nWrote enable=True -> read back: {device.read('enable')}")

        print("\nPolling... (Ctrl+C to stop)")
        while True:
            time.sleep(1)

    except KeyboardInterrupt:
        print("\nStopping...")
    finally:
        device.close()


if __name__ == "__main__":
    main()