Basic JSON structure of the event configuration
The JSON file created with the solution Litmus Production Record External Event Configurator, will include the JSON configuration for one or more events.
This allows, that more than one event can be monitored for example by the flow from the solution Litmus Production Record Event Processing Flow.
Each individual event consist of a unique event name of three sub sections.
The first sub section will hold the configuration for the trigger and is setup using the sheet Event_and_Trigger_Definition.
It consists of the a series of key-value pairs.
JSON key | What is defined | Example |
|---|---|---|
TriggerTagName | The DeviceHub Tag Name of the tag used as trigger tag. Note: The DeviceHub Device is not defined. This allows the flow using this configuration to monitor the same event for multiple devices if they all have the same tag. | ProgramName |
TriggerCondition | The condition used to monitor the tag value against. | OnValueChangeNotIncluded |
TriggerMonitorSource | If the TriggerCondition does require a value to check against, this key holds what the source of that value is. | ConstantValue |
TriggerMonitorValue | If the TriggerCondition does require a value to check against, this key holds that value. | O9 |
TriggerSecondMonitorSource | If the TriggerCondition does require a second value to check against, this key holds what the source of that value is. | FromFlowVariable |
TriggerSecondMonitorValue | If the TriggerCondition does require a second value to check against, this key holds that value. | IsMasterPart |
TriggerMsgCount | The number of data model items updated through this trigger | 5 |
EventUserTopic | The message broker topic prefix used to publish the data for the items updated through the trigger. | MSSQLData |
Each event has only one trigger condition.
The second sub section will hold the configuration for the Identifiers and is setup using the sheet Event_Identifier_Definition.
To learn more about Identifiers, please review the chapter How are data recorded in Litmus Production Record Database.
The sub section Identifier consist of 1-5 sub-keys called IdentifierTagRelation. How many of these sub-keys exist is based on how many Identifiers had been setup for the data model.
Each sub-key IdentifierTagRelation consists of a key-value pair and a JSON sub structure called IdentifierCollection.
JSON key | What is defined | Example |
|---|---|---|
TagName | The DeviceHub Tag Name of the tag used to to update the value of one or more Identifier(s). Note: The DeviceHub Device is not defined. This allows the flow using this configuration to monitor the same event for multiple devices if they all have the same tag. | SerialNumber |
IdentifierCollection | This JSON substructure consist of 1-5 sub-keys called ID. This allows to use the same DeviceHub Tag to update more than one Identifier Item, if they for example use both the value of the tag and the timestamp. Note: If a sub-key IdentifierCollection has 5 ID substructures, no additional IdentifierCollection sub-keys can exist, as only a maximum of 5 Identifiers can exist per data model. | |
Each substructure called ID consists of a series of key-value pairs.
JSON key | What is defined | Example |
|---|---|---|
TypeOfDataSource | This defines where the value for the Identifier is read from the DeviceHub tags message object. | FromTag |
IdentifierEvent | If the value for the Identifier is read from a different event, this hold the unique event name. | Status_Tracking_Asset |
IdentifierDevice | If the value for the Identifier is read from a different event and different DeviceHub device, this can be used to specify the DeviceHub device. | Line_PLC |
IdentifierValue | This is used to either provide a fixed value or specify the DeviceHub message object JSON key. | Value |
IdentifierName | This is a data model Item which has been set as Identifier for this data model. | Asset_Name |
Each event is required to have at least one and up to 5 IdentifierTagRelation sub-keys. Each of these sub-keys has at least One and up to 5 ID substructures.
Note: If one sub-key IdentifierCollection has 5 ID substructures, no additional IdentifierCollection sub-keys can exist, as only a maximum of 5 Identifiers can exist per data model.
The third sub section will hold the configuration for the Identifiers and is setup using the sheet Event_Item_Definition.
To learn more about data models used to store event data in Litmus Production Record Database, please review the chapter Core Concept behind recording production record data via data model.
The sub section Items consist of 1-n sub-keys called ItemTagRelation. How many of these sub-keys exist is based on how many Items are to be updated by the event.
Each sub-key ItemTagRelation consists of a key-value pair and a JSON sub structure called ItemCollection.
JSON key | What is defined | Example |
|---|---|---|
TagName | The DeviceHub Tag Name of the tag used to update the value of one or more Item(s). Note: The DeviceHub Device is not defined. This allows the flow using this configuration to monitor the same event for multiple devices if they all have the same tag. | SerialNumber |
ItemCollection | This JSON substructure consist of 1-n sub-keys called Item. This allows to use the same DeviceHub Tag to update more than one Item, if they for example use both the value of the tag and the timestamp or are a constant value. | |
Each substructure called Item consists of a series of key-value pairs.
JSON key | What is defined | Example |
|---|---|---|
ItemName | The name of the data model Item. | SerialNo |
NodeNameSource | The source where the flow reads the data model name from | ConstantValue |
NodeName | The value or source of the data model name | Geometry |
LevelName | A pipe symbol "|" separated string of the hierarchy level names under which the Item resides in the data model. | Gauge|Actual |
isIdentifier | Is the Item an Identifier? | Yes |
SendAtStartEnd | If the trigger does execute, is the value written to the new event or to the previous event? | NewEvent |
ValueSource | Defines the source of the value for the Item | FromTag |
Value | This is used to either provide a fixed value or specify the DeviceHub message object JSON key. | |
Each event is required to have at least one ItemTagRelation sub-keys. Each of these sub-keys has at least One Item substructure.
