x/modbusRead component: v0.37.0+ batch-reads Modbus points over TCP/RTU. Results are written back to msg.Data as a list of the unified contract iot_points.Data, routing to Success/Failure.

Unlike the imperative x/modbus (single Cmd/Address/Quantity), this component is point-table oriented, uses the industry-standard Modicon traditional addresses, and produces output consistent with s7/eip/snmp/opcua — ready to feed x/tsdbWrite (with measurement configured) for time-series storage.

Requires the extension library: rulego-components-iot (opens new window)

Configuration

Field	Type	Description	Default
server	string	Modbus server address (tcp://host:port or rtu:///dev/ttyUSB0)	tcp://127.0.0.1:502
unitId	uint8	Slave unit ID	1
points	array	Default point table (see below). Points in msg.Data take precedence	none
tcpConfig	object	TCP config (timeout/certFile/certKeyFile/caFile)	none
rtuConfig	object	RTU serial config (speed/dataBits/parity/stopBits)	none
encodingConfig	object	Encoding (endianness/wordOrder for multi-register values)	big-endian high-word

Point table (points)

Field	Description
name	Point name (becomes the Data name)
addr	Modicon address (1-based): 00001=Coil, 10001=Discrete Input, 30001=Input Register, 40001=Holding Register; extended 6-digit 400001+ = Holding Register
type	Data type: BOOL/UINT16/INT16/UINT32/INT32/UINT64/INT64/FLOAT32/FLOAT64
scale	Scale factor: engineering = raw × scale + offset
offset	Offset
endian	Multi-register byte order: ABCD/CDAB/BADC/DCBA

All fields support ${msg.xx} / ${metadata.xx} templates.

Output

msg.Data (unified contract, same as s7/eip/snmp/opcua):

[
  {"name": "temperature", "value": 23.5, "timestamp": 1789999999000000000},
  {"name": "motor", "value": true, "timestamp": 1789999999000000000}
]

Example

Scheduled acquisition (schedule endpoint in front), points in points:

{
  "id": "modbus_read",
  "type": "x/modbusRead",
  "configuration": {
    "server": "tcp://192.168.1.100:502",
    "unitId": 1,
    "points": [
      {"name": "temp", "addr": "40001", "type": "FLOAT32", "scale": 0.1},
      {"name": "motor", "addr": "00001", "type": "BOOL"}
    ]
  }
}

On-demand read (points in msg.Data take precedence):

[{"name": "setpoint", "addr": "40010", "type": "FLOAT32"}]

Related

• Write: x/modbusWrite
• Universal acquisition entry: x/iotRead
• To time-series storage: x/tsdbWrite (measurement configured)
• Imperative (legacy): x/modbus (kept; output also unified to iot_points.Data)