JSON Configuration

JSON configuration is useful for field delivery: ports, unit ids, point maps, and acquisition intervals live in a file that can be changed without recompiling.

Minimal File

zeus.json:

{
  "acquisition": {
    "intervalMilliseconds": 500,
    "pollImmediately": true
  },
  "channels": [
    {
      "name": "bus",
      "type": "serial",
      "portName": "COM3",
      "baudRate": 9600
    }
  ],
  "devices": [
    {
      "name": "oven",
      "channel": "bus",
      "type": "modbus-rtu",
      "unitId": 1,
      "points": [
        { "name": "temperature", "table": "holding", "address": 0, "scale": 0.1, "lowAlarmLimit": 10, "highAlarmLimit": 80 },
        { "name": "setpoint", "table": "holding", "address": 1, "scale": 0.1, "writable": true }
      ]
    }
  ]
}

Load it:

await using var app = ZeusHost.Create(builder => builder.AddJsonFile("zeus.json"));
await app.StartAsync();

var temperature = app.Points.Get<double>("temperature");

Sections

Section	Meaning
acquisition	Polling interval and whether to poll immediately after startup
channels	Communication lines such as serial, TCP, UDP, and virtual channels
devices	Devices such as Modbus, Mitsubishi MC, Siemens S7, Omron FINS, Omron Host Link, or EtherNet/IP
points	Business points on a device, such as temperature, setpoint, or running state

Each device channel must reference an already declared channel name.

Virtual Configuration Without Hardware

Replace a serial channel with a virtual Modbus slave:

{
  "name": "bus",
  "type": "virtual",
  "responder": "modbus",
  "unitId": 1,
  "transport": "rtu"
}

When the field device is ready, switch back to serial:

{
  "name": "bus",
  "type": "serial",
  "portName": "COM3",
  "baudRate": 9600
}

Channel Fields

Field	Applies to	Meaning
name	all	Zeus channel name
type	all	virtual, serial, tcp, tcp-server, udp, or udp-server
portName / baudRate	serial	COM port and baud rate
host / port	tcp / udp	Remote host and port
localAddress / localPort	server channels	Local bind/listen settings
responder	virtual	modbus, mc, s7, fins, host-link, or ethernet-ip

Device Fields

Field	Meaning
name	Zeus device name
channel	Channel name to bind
type	modbus-rtu, modbus-tcp, mitsubishi-mc, siemens-s7, omron-fins-udp, omron-fins-tcp, omron-host-link, or ethernet-ip
unitId	Modbus unit id or Host Link unit number; Host Link uses 0-31
frameType / encoding	Mitsubishi MC frame and encoding
rack / slot	Siemens S7 rack and slot
FINS node/network fields	FINS destination/source addressing
wordOrder	FINS / Host Link 32-bit value word order
points	Periodically acquired points and writable declarations

Point Fields

Field	Meaning
name	Point name
table	Modbus table: holding, input, coil, or discrete
deviceCode	Mitsubishi MC device code: D, M, X, Y, W, R, ZR
area	S7/FINS/Host Link area
tag / tagName	EtherNet/IP tag path
dataType	Protocol-specific point type
address	0-based address; strings such as "0x10" are accepted where applicable
bit	Bit offset for bit points
scale	Engineering scale for numeric points
lowAlarmLimit / highAlarmLimit	Alarm thresholds after scaling
writable	Enables write-back by point name

Host Link Example

{
  "channels": [
    { "name": "host-link", "type": "serial", "portName": "COM3", "baudRate": 9600 }
  ],
  "devices": [
    {
      "name": "plc",
      "channel": "host-link",
      "type": "omron-host-link",
      "unitId": 0,
      "points": [
        { "name": "temperature", "area": "dm", "address": 100, "dataType": "word", "scale": 0.1, "writable": true },
        { "name": "running", "area": "cio", "address": 10, "bit": 0, "dataType": "bit", "writable": true }
      ]
    }
  ]
}

Virtual Host Link PLC:

{ "name": "host-link", "type": "virtual", "responder": "host-link", "unitId": 0 }

Sample JSON files live under samples/Zeus.Samples.Console.Config.