...
Then you can change any of the values on the outputs here:
You should see the output value change. By changing an output what happens is a DCMD MQTT message is constructed in MQTT Engine and published to the MQTT Server. This message is then sent to the sample client where it is received. In a real scenario the device side code should write the the actual output at this point and read back the value. In that case and in this emulated case, a DDATA message is constructed and published to the MQTT server. It is then received by MQTT Engine and where the state of the tag is updated.
This sample code also includes code that constructs the following message types:
- Sparkplug Templates which are converted to Ignition UDTs by MQTT Engine
- Datasets
- Sparkplug Properties which are converted to Ignition Tag Properties
- In order for these to show up in Ignition they must be known Ignition properties such as engUnit, engLow, engHigh, and Quality,
This example also utilizes aliases to prevent the need to send metric names on any message other than the initial NBIRTH and DBIRTH messages.
