Re: [sparkplug-wg] How to support SCADA to device command in a Non-Persi

[Bryce Nakatani <bnakatani@xxxxxxxxxx>]

Your understanding of Sparkplug is correct. There isn't a queuing of writes when a node is offline.

At the SCADA layer, you should be able to monitor the online status of the node. Should the node be offline, queue writes and when the node is online, release the writes.

On Mon, Jun 17, 2024 at 10:25 PM wang ge via sparkplug-wg <sparkplug-wg@xxxxxxxxxxx> wrote:

Hi team,

I am now designing a battery powered cellular connected measurement device and according to the requirement, it needs to talk to SCADA through SparkPlug B over Cellular Network.

Since the device is battery powered, we cannot make it Persistent online, due to power consumption reason(We only power on cellular module when the periodic report time is reached).

I think it is not a problem for uplink measurement data report.

However, if we look at the remote device configuration from SCADA to the device, I think there is a problem: As the device is not always online and according to the Sparkplug B spec, the SCADA(host application) and the MQTT Broker in the system will not buffer the downlink message when the device is offline which means the device is remote reachable only when it trying to report measurement data to the host.

So, my question is the downlink message feature(from host application to device) in SparkPlug B is only designed for Persistent scenario or is there any misunderstanding by us that we did not use it correctly?

Thanks so much for your kindly help!

Best Regards,

Jimmy

_______________________________________________
sparkplug-wg mailing list
sparkplug-wg@xxxxxxxxxxx
To unsubscribe from this list, visit https://www.eclipse.org/mailman/listinfo/sparkplug-wg