Tags
Tags are the single units of data collection from a device. Once you connect a device to Litmus Edge, you add tags to that device. Tags map to the device's registers from which you want DeviceHub to collect data. Every device has memory registers that store sensor and system values. These registers can be analog and digital, input and output. Register information is accessed as tags and these tags are published as Topics to the internal Message Broker.
When you Connect a Device, you have the option of generating raw topics or alias topics. Alias topics consist of devicename and tagname instead of DeviceID and TagID. Topics can be used for publishing and subscribing with an internal message broker. Raw or processed data can be analyzed at the edge using Analytics or flows in Flows Manager. You can publish data to Litmus Edge Manager through raw topics.
You can add tags as follows:
- Add a tag: Adds a single tag for the selected device.
- Upload CSV: Uploads a list of tags from a CSV file.
- Browse Tags: Search for pre-defined device tags and select the ones to add. See Search for Pre-defined Device Tags to learn more.
See Default Topics and Descriptions for information about topic formats.
If you select Enable alias topics while adding or modifying a device:
- The Topic ID is replaced with a name (for example, devicehub.alias.PLC1.floatTag)
- DeviceHub stops publishing to raw topics and publishes only to alias topics.
- Litmus Edge substitutes all special characters in aliases with "_" (underscore).
- Message broker allows subscribe and publish of Raw/Alias topics.
- When alias topics are enabled for a device, you can't use batch write topics. To use batch write topics, you must not select the Enable alias topics check box in the device configuration. See Default Topics and Descriptions for more information.
You can access Tags from the DeviceHub.
To access Tags:
- Log in to Litmus Edge.
- From the Navigation panel, navigate to DeviceHub > Tags. The Tags pane appears.
