MQTT Sending - “Parameters” -> “Subscribe”

Subscribe: Configuration of the subscribe parameters.

• Subscribe Parameters: In this section the subscribe parameters can be defined. It is possible to subscribe to one or more Topics in the same session.

A Sender channel can simultaneously subscribe to one or more Topics. This would be done by checking the Subscribe to Additional Topics option and filling in the table with the specified values.

The example of the image represents two Topics: Topic1 and Topic2, descending from the Topic TechedgeGroup; however, the channel could subscribe to that topic directly, TechedgeGroup, so it would be subscribed to each Topic descending from TechedgeGroup.

• Payload Parameters: 

Finally, it can be defined if the message will be encoded in Base64. In this way, it is possible to decode the message checking in "Base64 decode received message" and setting the encoding in the “Message Encoding” box, so SAP PI can process it.

Furthermore, if the chosen message protocol is XML, an additional decoding option with a Xpath expression can be chosen and the encoding can be set:

Using this option, only the text inside the tag indicated in the Xpath expression is decoded. In the example of the image, the output will be the full message with the decoded text of the “name” tag.