Data to server MQTT buffering messages

[nmenoni]

Hi, I have multiples RUT200s where I’m reading some variables using Modbus and sending the data to a cloud platform using the “Data to server” feature. In particular I’m using MQTT option.

The issue I’m facing is that when the internet connection drops for some time, all generated messages are queued and when the connection is reestablish all the queued messages are sent, which in my use case is not desirable. I’m using QoS 0.

The same happens for the events sent using “Event juggler” + MQTT.

Based on some research I’ve made, it looks like the MQTT clean session option could help to avoid this behaviour, so when the connection with the broker is broken it will not queue the pending messages. The things is that I’m not able to find a way to configure it in the RUT200.

Any tips or help?

Thank you

[Martynas]

Hello,

Thank you for reaching out.

Unfortunately, currently there is no option to disable the Modbus database mechanism, which means it will queue and push all collected data gathered during an internet connection loss once the connection is restored.

However, there is a helpful alternative you might consider: in the Modbus Client Request settings, you can enable the Store data on change only option:

With this enabled, the device will only store and subsequently push data via the Data to Server when a Modbus value actually changes. If the data remains constant during the offline period, it won’t get queued or sent when the connection comes back.

Best regards,