Merge pull request #205007 from dominicbetts/central-mapping-unmodeled

IoT Central: unmodeled mapping example

Author: PMEds28

articles/iot-central/core/howto-map-data.md

@@ -72,9 +72,9 @@ To verify that IoT Central is mapping the telemetry, navigate to **Raw data** vi
 
 If you don't see your mapped data after refreshing the **Raw data** several times, check that the JSONPath expression you're using matches the structure of the telemetry message.
 
-For IoT Edge devices, the data mapping applies to the telemetry from all the IoT Edge modules and hub. You can't apply mappings to a specific IoT edge module.
+For IoT Edge devices, the data mapping applies to the telemetry from all the IoT Edge modules and hub. You can't apply mappings to a specific Azure IoT Edge module.
 
-For devices assigned to a device template, you can't map data for components or inherited interfaces. However, you can map any data from your device before you assign it to a device template.
+For devices assigned to a device template, you can't map data for components or inherited interfaces. However, you can [map any data from your device before you assign it to a device template](#map-unmodeled-telemetry).
 
 ## Manage mappings
 
@@ -84,6 +84,71 @@ To view, edit, or delete mappings, navigate to the **Mapped aliases** page. Sele
 
 By default, data exports from IoT Central include mapped data. To exclude mapped data, use a [data transformation](howto-transform-data-internally.md) in your data export.
 
+## Map unmodeled telemetry
+
+You can map unmodeled telemetry, including telemetry from unmodeled components. For example, given the `workingSet` telemetry defined in the root component and the `temperature` telemetry defined in a thermostat component shown in the following example:
+
+```json
+{
+  "_unmodeleddata": {
+    "workingSet": 74
+  },
+  "_eventtype": "Telemetry",
+  "_timestamp": "2022-07-18T09:22:40.257Z"
+}
+
+{
+  "_unmodeleddata": {
+    "thermostat2": {
+      "__t": "c",
+      "temperature": 44
+    }
+  },
+  "_eventtype": "Telemetry",
+  "_timestamp": "2022-07-18T09:21:48.69Z"
+}
+```
+
+You can map this telemetry using the following mapping definitions:
+
+* `$["workingSet"] ws`
+* `$["temperature"] temp`
+
+> [!NOTE]
+> Don't include the component name in the mapping definition.
+
+The results of these mapping rules look like the following examples:
+
+```json
+{
+  "telemetries": {
+    "workingSet": 84,
+    "_mappeddata": {
+      "ws": 84
+    }
+  }
+}
+
+{
+  "_unmodeleddata": {
+    "thermostat2": {
+      "__t": "c",
+      "temperature": 12
+    },
+    "_mappeddata": {
+      "thermostat2": {
+        "__t": "c",
+        "temp": 12
+      }
+    }
+  },
+  "_eventtype": "Telemetry",
+  "_timestamp": "2022-07-18T09:31:21.088Z"
+}
+```
+
+Now you can use the mapped aliases to display telemetry on a chart or dashboard. You can also use the mapped aliases when you export telemetry.
+
 ## Next steps
 
 Now that you've learned how to map data for your device, a suggested next step is to learn [How to use data explorer to analyze device data](howto-create-analytics.md).