SCADA · Schema

ScadaTag

Schema for a SCADA data tag representing a sensor reading, setpoint, or control variable

Critical InfrastructureICSIndustrial AutomationIndustrial IoTOT SecuritySCADA

Properties

Name Type Description
tagId string Unique identifier for the tag in the SCADA system
tagName string Human-readable name for the tag
tagPath string Hierarchical path to the tag in the SCADA tag browser
value object Current value of the tag (type depends on dataType)
dataType string Data type of the tag value
timestamp string ISO 8601 timestamp of the tag reading
quality string OPC-UA quality code indicating data reliability
engineeringUnits string Physical engineering units for the tag value
description string Human-readable description of what the tag measures
alarmLimits object Configured alarm threshold limits for the tag
deviceSource object Source field device information
processArea string Logical process area or plant unit this tag belongs to
View JSON Schema on GitHub

JSON Schema

scada-tag-schema.json Raw ↑ 
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://raw.githubusercontent.com/api-evangelist/scada/main/json-schema/scada-tag-schema.json",
  "title": "ScadaTag",
  "description": "Schema for a SCADA data tag representing a sensor reading, setpoint, or control variable",
  "type": "object",
  "properties": {
    "tagId": {
      "type": "string",
      "description": "Unique identifier for the tag in the SCADA system",
      "example": "PLANT1.AREA2.PV_101"
    },
    "tagName": {
      "type": "string",
      "description": "Human-readable name for the tag",
      "example": "Reactor Inlet Pressure"
    },
    "tagPath": {
      "type": "string",
      "description": "Hierarchical path to the tag in the SCADA tag browser",
      "example": "Plant/Area2/Reactor/PV_101"
    },
    "value": {
      "description": "Current value of the tag (type depends on dataType)",
      "example": 14.7
    },
    "dataType": {
      "type": "string",
      "description": "Data type of the tag value",
      "enum": ["Float", "Double", "Integer", "Boolean", "String", "DateTime"],
      "example": "Float"
    },
    "timestamp": {
      "type": "string",
      "format": "date-time",
      "description": "ISO 8601 timestamp of the tag reading",
      "example": "2026-05-02T14:30:00.000Z"
    },
    "quality": {
      "type": "string",
      "description": "OPC-UA quality code indicating data reliability",
      "enum": ["Good", "Uncertain", "Bad", "Stale"],
      "example": "Good"
    },
    "engineeringUnits": {
      "type": "string",
      "description": "Physical engineering units for the tag value",
      "example": "PSI"
    },
    "description": {
      "type": "string",
      "description": "Human-readable description of what the tag measures",
      "example": "Pressure at reactor inlet measured by differential pressure transmitter PV-101"
    },
    "alarmLimits": {
      "type": "object",
      "description": "Configured alarm threshold limits for the tag",
      "properties": {
        "highHigh": {
          "type": "number",
          "description": "High-High alarm setpoint (critical)"
        },
        "high": {
          "type": "number",
          "description": "High alarm setpoint (warning)"
        },
        "low": {
          "type": "number",
          "description": "Low alarm setpoint (warning)"
        },
        "lowLow": {
          "type": "number",
          "description": "Low-Low alarm setpoint (critical)"
        }
      }
    },
    "deviceSource": {
      "type": "object",
      "description": "Source field device information",
      "properties": {
        "deviceId": {
          "type": "string",
          "description": "Identifier of the PLC or RTU providing the tag"
        },
        "deviceType": {
          "type": "string",
          "description": "Type of source device",
          "enum": ["PLC", "RTU", "DCS", "IED", "Sensor", "Controller"]
        },
        "protocol": {
          "type": "string",
          "description": "Communication protocol used to read this tag",
          "enum": ["Modbus-TCP", "OPC-UA", "DNP3", "EtherNet/IP", "PROFINET", "BACnet", "MQTT"]
        }
      }
    },
    "processArea": {
      "type": "string",
      "description": "Logical process area or plant unit this tag belongs to",
      "example": "Reactor Section"
    }
  },
  "required": ["tagId", "value", "dataType", "timestamp", "quality"],
  "additionalProperties": false
}