Introduced in V5.03.01 onwards of EasyBuilder Pro is an MQTT object for the XE Series HMI.
MQTT is a lightweight machine to machine (M2M) “Internet of Things” (IoT) protocol & stands for “MQ Telemetry Transport”, it’s a publish/subscribe, simple and lightweight messaging protocol, designed for low-bandwidth, high-latency or unreliable networks.
Users “subscribe” to their chosen “Topics” with an MQTT client. A topic is a UTF-8 string used by the broker to filter messages for each connected client. Topics consists of one or more topic levels. Each topic level is separated by a forward slash (topic level separator). Different users can subscribe to different topics of interest, maintainence for example will have interest in different topics to production or management.
How does MQTT fit in with the HMI?
The XE Series HMI gathers data from your connected controller or other devices. There are two publish methods for the HMI, 1 – using either an external broker, or 2 – Using the internal broker, both are described below.
Ideal for an HMI that is behind a firewall. There are many Cloud based brokers out there to choose from, or you may even host your own.
Alternatively, MQTT messages can be published internally to the built-in MQTT broker so an external broker is not necessary. Using an MQTT client, you can to subscribe directly to the broker inside the HMI and receive message updates! This scheme can be used remotely so long as the MQTT client can connect directly to HMI, via VPN or EasyAccess 2.0.