Trigger Schemes

Scripts use Lua syntax. For overall concepts, including trigger-condition and action categories, first read Trigger schemes. This page details write parameters, return structures, and complete examples for EXPRESSION trigger-action scripts.

Overview

1. Trigger logic matches other scheme types; the difference is the action’s script content.
2. After script execution, the Edge-EMS Builder backend parses the returned result and writes the specified points accordingly.

Note: users need basic programming knowledge and familiarity with strategy execution. For script syntax, see the Lua engine reference.

Usage

Write parameters

Parameter	Value	Required	Type	Description
dataType	Customization	Yes	String	Data type to operate on: Customization/Collection/Aggregation/Alarm/Share
deviceCode	DeviceA	No	String	Slave-device code
dataKey	功率	Yes	String	Unique dataKey or alarm type
dataValue	15	Yes	String	Data value or alarm content
changeMod	true	No	String	Whether to enable writing only on change
availableDate	2023-01-15T07:00:00+08:00	No	String	Effective date (Customization)
expiredDate	2023-01-15T10:00:00+08:00	No	String	Expiration date (Customization)
mqttConnectionConfigId	100101	No	String	MQTT connection configuration ID (Alarm)
topic	upload	No	String	Alarm upload topic (Alarm)
qos	1	No	String	QoS (Alarm)

Time-scheduled data (Customization) also supports daily repeating (DailyRepeat) schedules. Use availableTime/expiredTime in HH:mm:ss format, without crossing midnight, instead of availableDate/expiredDate to repeat daily. Use the shorthand buildCustomizationWriteMap(dataKey, dataValue, availableDate, expiredDate) for DailyChange or buildDailyRepeatWriteMap(dataKey, dataValue, availableTime, expiredTime) for DailyRepeat. See the Lua engine reference.

Unavailable referenced points are injected as the sentinel string __Null__. Do not assume an empty string or nil; explicitly check ${dataKey} == "__Null__".

Example

local resultList = {}

-- Custom alarm content
local errorMap = {}
errorMap.timestamp = OffsetDateTime.now():unixMilli()
errorMap.iotCode = ${数据9}
errorMap.faultCode = ${数据9}
errorMap.faultLevel = ${数据9}
errorMap.faultName = ${数据9}
errorMap.faultBack = ${数据9}
-- Convert alarm content to JSON
local errorMessage = toJsonString(errorMap)

table.insert(resultList, buildCommonWriteMap("Customization", "mode", 15, "2023-01-15T07:00:00+08:00", "2023-01-15T10:00:00+08:00", true))
table.insert(resultList, buildCommonAlarmMap("二级告警", "二级告警"))
table.insert(resultList, buildMqttAlarmMap("一级告警", errorMessage, 1, "upload", 1))
table.insert(resultList, buildCommonWriteMap("Collection", "数据10", 200, nil, nil, true))
table.insert(resultList, buildCommonWriteMap("Aggregation", "温度", 20, nil, nil, false))
table.insert(resultList, buildSlaveWriteMap("DeviceB", "Share", "数据3", 888, nil, nil, false))

return resultList

Expected execution result

Return an array containing multiple Tables. Edge-EMS Builder parses it, validates each object’s contents, then returns the encapsulated write objects:

[
  {
    "dataType": "",//Target object
        "deviceCode": "",//Unique slave-device code identifying the device to write to
    "dataKey": "",//Unique target key: dataKey or alarmType
    "dataValue": "",//Value to write or alarm content
        "changeMod": true,//Whether to write only on change
    "availableDate": "",//Time-scheduled data effective time
    "expiredDate": ""//Time-scheduled data expiration time
  }
]

Parsed result

Parse the execution result, validate its contents, and return encapsulated objects prepared for execution:

{
    "writeCommBridgeContent": [
        {
            "dataKey": "数据10",
            "dataValue": "200"
        }
    ],
    "writeAggregationDataConfigs": [
        {
            "aggregationDataConfigId": 100004,
            "dataKey": "温度",
            "dataName": "温度",
            "collectionCycle": -1,
            "expression": "return 15",
            "status": "Valid",
            "empty": false,
            "hasGroup": false,
            "useLatestValue": true,
            "note": "",
            "createdBy": 100001,
            "createdTime": "2025-03-18T15:04:39.503+08:00",
            "updatedBy": 100001,
            "updatedTime": "2025-03-28T10:21:15.578+08:00"
        }
    ],
    "writeAggregationDataValues": [
        {
            "aggregationDataConfigId": 100004,
            "dataValue": "20",
            "collectionTime": "2025-04-23T15:30:49.913+08:00"
        }
    ],
    "writeCustomizationDataValues": [
        {
            "customizationDataConfigId": 100003,
            "dataValue": "15",
            "availableDate": "2023-01-15T07:00:00.000+08:00",
            "expiredDate": "2023-01-15T10:00:00.000+08:00",
            "createdBy": 100000,
            "createdTime": "2025-04-23T15:30:49.912+08:00"
        }
    ],
    "writeShareDataValues": [
        {
            "shareDataConfigId": 3,
            "deviceCode": "DeviceB",
            "dataKey": "数据3",
            "collectionCycle": 3000,
            "dataValue": "888",
            "collectionTime": "2025-04-23T15:30:49.914+08:00"
        }
    ],
    "alarmRecords": [
        {
            "alarmType": "二级告警",
            "alarmContent": "二级告警",
            "alarmTime": "2025-04-23T15:30:49.912+08:00",
            "mark": "None"
        },
        {
            "alarmType": "一级告警",
            "alarmContent": "{\"iotCode\":66.60000000,\"faultCode\":66.60000000,\"faultBack\":66.60000000,\"faultLevel\":66.60000000,\"timestamp\":1745393449910,\"faultName\":66.60000000}",
            "alarmTime": "2025-04-23T15:30:49.912+08:00",
            "mark": "None",
            "mqttConnectionConfigId": 1,
            "topic": "upload",
            "qos": 1
        }
    ]
}

MQTT alarm upload result

Next steps

• Overall trigger concepts, condition/action types, and dynamic device discovery: Trigger schemes.
• Complete Lua built-in function and module reference: Lua engine reference.