Connect a machine via MQTT

If a machine is to be connected to an asset, there are now 2 options available.

1. Indirect connection via x4remote, which is described in the article https://ll-public.atlassian.net/wiki/spaces/X4/pages/303988737.

2. Direct connection to the platform via MQTT.

The connection via MQTT using the example of the Lenze x500 is the topic of this article.

General

An MQTT telegram consists of a topic and a payload. In addition, a router also requires connection data such as URL and access data in order to be able to send its telegrams to a broker. All this information - URL, access data, server certificate and topic - is specified by the Asset Performance Platform and must be set in the router.

The Asset Performance Platform provides a broker that only allows an encrypted and authenticated connection.

The MQTT protocol specification does not define how the payload must be designed. This gap is filled by the Sparkplug B specification for MQTT user data.

The Lenze x500 transmits its data Sparkplug B compliant. The Asset Performance Platform can read the payload in Sparkplug B format. With the restriction that the payload must be formatted as plain text JSON. The use of the Google Protocol Buffer Schema, as described in the specification, is in preparation.

A payload in Sparkplug B format is as follows:

{
  "timestamp": <send timestamp>,
  "metrics": [{
    "name": <metric_name>,
    "alias": <alias>,
    "timestamp": <collect timestamp>,
    "dataType": <datatype>,
    "value": <value>
  }],
  "seq": <sequence_number>
}

The keys from top to bottom are to be understood as follows:

Example payload:

{
	"metrics": [
		{
			"alias": 2,
			"datatype": 9,
			"name": "scCloud_rOEErt",
			"timestamp": 1721829360000,
			"value": 75.28211975097656
		},
		{
			"alias": 11,
			"datatype": 10,
			"name": "scCloud_lrQuantityOK",
			"timestamp": 1721829360000,
			"value": 3589.0
		}
	],
	"seq": 215,
	"timestamp": 1721829360042
}

Settings in the Asset Performance Platform

To create a connection for an asset, the configuration dialog can be called up via the connection icon.

The connection type can be selected in this dialog. The entry “x500 via MQTT” must be selected here.

The selection can then be confirmed with “Save”, as no further settings are required. The connection data is now generated by the system. This connection data must now be set in the router, which depends on the router manufacturer. The next section describes this for the x500 as an example.

In addition to the access data, the server certificate can be downloaded here. This is necessary so that the client can check the connection.

These connection settings can be displayed again at any time in the same way.

Settings in the x500 or x4remote

comming soon.

Data type list