This section describes the topic structure for Data and Metadata. The recommended structure of topic naming is as follows:
Tags data
ie/d/j/simatic/v1/s7c1/dp/r/#
It is made of the following elements:
ie/{payloadType}/{encoding}/{msgStructureScheme}/{msgStructureSchemeVersion}/{provideAppInstanceId}/{payloadMsgType}/{accessmode}/{connectionname}/{collectionname}
Tags metadata
ie/m/j/simatic/v1/s7c1/dp
It is made of the following elements:
ie/{payloadType}/{encoding}/{msgStructureScheme}/{msgStructureSchemeVersion}/{provideAppInstanceId}/{payloadMsgType}
The following table explains the above elements:
| Quality | ||
|---|---|---|
| Element | Description | Possible Values |
| payloadType | This indicates what the payload contains. | 'd' for data 'm' for metadata |
| encoding | This indicates payload encoding. | 'j' for JSON |
| msgStructureScheme | This indicates payload format schema model. | simatic |
| msgStructureSchemeVersion | This indicates payload format schema version number | v1 |
| provideAppInstanceId | This indicates unique id of provider app. | 's7c1' for SIMATIC S7 Connector instance 1 |
| payloadMsgType | This indicates payload message content. | 'dp': DataPoints for PLC Variables (process image) 'ev': Events for PLC Fulltext Alarms, HMI Alarms |
| accessmode | This is an app specific element. This indicates the purpose of the payload for SIMATIC S7 Connector as it would support both read and write of Data Points. | 'r' for Read from Connectors 'w' for write to Connectors |
| connectionname | This is an app specific element. This indicates unique name provided in Connector for a connection to a PLC in SIMATIC S7 Connector. | Paintshop1PLC |
| collectionname | This is an app specific element. This indicates the collection name. | 'default' for Tags published in bulk mode |