MQTT Device list topic

[wsobel]

Create a topic that lists all the devices as a JSON array of name, uuid, and relates topic.

What should the topic be?

Does the payload make sense?

[robot-ranger]

maybe im missing something...but isnt this what probe is for?

[wsobel]

This is what the probe is for. The MQTT implementation breaks the document into separate devices.

We could have a single probe payload, that would be an option. Or we can provide a separate device list. If you subscribe to MTConnect/Probe/#, you will effectively get all the devices.

[robot-ranger]

i think im following you now. the agent could be configured with user-customized topic prefixes. So youre suggesting a topic with payload like the following to inform client apps of where to look for their device of interest; is that right?

{
	"myDeviceA_UUID":{
		"id": "deviceA_ID",
		"name": "deviceA_NAME",
		"topics":{
			"probe": "MTConnect/Probe/myDeviceA_UUID",
			"current": "MTConnect/Current/myDeviceA_UUID",
			"sample": "MTConnect/Sample/myDeviceA_UUID"
		}
	},
	"myDeviceB_UUID":{
		"id": "deviceB_ID",
		"name": "deviceB_NAME",
		"topics":{
			"probe": "MTConnect/Probe/myDeviceB_UUID",
			"current": "MTConnect/Current/myDeviceB_UUID",
			"sample": "MTConnect/Sample/myDeviceB_UUID"
		}
	}
	# ... rest of devices
}

[emvarunp]

Hi @wsobel. The payload makes sense.

We usually subscribe to probe/# to get the UUID of a device. But having a seperate topic like mtconnect/devices or mtconnect/probe/devices which gives a list of devices info would be very helpful.

Thank you.