基于MQTT的OPC UA快速开发.pdf

1、OPC Day International 2024June 17th 21st,2024Randy ArmstrongChair of OPC UA Security Working Grouprandy.armstrongopcfoundation.orgOPC Day International 2024June 17th 21st,2024Client-Server=tightly coupled applications.Browsing address space to discover;Client specific subscriptions.Subscriptions cha

2、nge frequently.Need to call Methods.PubSub=loosely coupled applications.No need to browse;Many Clients can use same subscription;Subscriptions change rarely;Limited need for Methods.ClientServerPublisherSubscriberSubscriberSubscriberMQTTBrokerOPC Day International 2024June 17th 21st,20243PubSub may

3、be an add-on to a Server.A Publisher is a Client subscribing for data which is it re-publishes.A Client is used to configure the Publisher.Same data and information models can be published with PubSubClientServerPublisherSubscriberPubSubConfigurationSubscriberSaved In StorageIndustrial ProcessMQTTBr

4、okerOPC Day International 2024June 17th 21st,20244PubSub stands on its own!Publisher configuration can be fixed or managed with a non-OPC UA applicationPublisher sends fixed messages and metadata to MQTT broker.Subscribers discover where and what is Published by subscribing to well known topics.Subs

5、criberPubSubConfigurationSubscriberSaved In StorageIndustrial ProcessPublisherMQTT BrokerOPC Day International 2024June 17th 21st,20245MeasurementDescriptionUnitsConsumptionThe energy consumed by the device during the calculation period.kWhDutyCycleThe fraction of the calculation period where the de

6、vice is consuming power.%CalculationPeriodThe period,in ms,over which power calculations are computed.sOPC Day International 2024June 17th 21st,20246JSON widely understood.Default data format for the web GZIPed JSON smaller than most binary formatsOPC UA over MQTT uses JSON as the primary interchang