Hello,

I am using Codesys sp20p3 and IIoT library 1.11.
I am trying to test QoS 1 & 2 and I have some issues.

I am using mosquitto as the broker. I am also using some other MQTT clients like Node-Red and TwinCAT. They all work as expected for every QoS levels. I only have issues with Codesys MQTT client.

In the Codesys client, if I subscribe to a topic as QoS 1 or 2, and a client publishes to this topic, I receive the message. But if I disconnect the Codesys client from the network and a client publishes to the subscribed topic, when I reconnect Codesys client to the network, I don't receive the messages as expected. Also there does not seem to be an auto-reconnect feature. So I have to manually set the mqttClient.xEnable bit to FALSE then back to TRUE in order to reconnect to the broker, then I also have to set the subscribe.xEnable to FALSE and back to TRUE in order to re-subscribe to the topic, but even then, I don't receive the messages that were published while I was disconnected. What am I doing wrong?

I set the cleanSession bit to FALSE and I give my client a clientID.

With the TwinCAT MQTT Client, I do the same thing and everything works as expected. It even auto-reconnects to the broker. I would expect Codesys MQTT Client to be as reliable as TwinCAT. Maybe I am doing something wrong?

I also noticed that when trying to publish a QoS 1 or 2 message while disconnected from the broker, it does not work. In TwinCAT, I am still able to publish. The messages are stored in the client and published once reconnected to the broker. I would expect to be able to do the same thing in Codesys.

Is this all possible? Am I doing something wrong?

Thank you