Sparkplug driver - Cannot disable STATE (SCADA Host ID)

[jbrzozoski]

I have been trying to help one of our customers connect their GeoScada server into a pre-existing Sparkplug/MQTT broker cloud. This particular MQTT broker has a strict ACL and does not allow most servers to announce STATE. Some of the edge nodes cannot be configured to pay attention to only certain server names, and it is not desirable to have them publishing if the core servers are offline. So, instead, the broker only allows the core servers to publish STATE.

We cannot find any way to get GeoScada to NOT publish STATE, and so the broker is rejecting the CONNECT requests because the MQTT LWT is on a topic that the GeoScada client is not allowed to publish to.

Is there some way to configure GeoScada to not publish STATE? If not, is this something that could be implemented?

[sbeadle]

Hi,

I can see the issue, and that looks like we need to ask for a new feature - to disable the STATE publish/subscribe in the Geo SCADA Driver.

I can't think of an easy workaround for this, except using an intermediate broker to route/drop these messages as appropriate?

The current Sparkplug specification is therefore likely wrong! It states in section 1.4.1: "[tck-id-intro-sparkplug-host-state] Sparkplug Host Applications MUST publish STATE messages denoting their online and offline status. " 

It should use the term Primary Host Application.

S