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grig100 · Member 3 Joined: 01 Jan 2015 Posts: 752

MQTT Publisher for SIMATIC S7-1500 CPU
https://support.industry.siemens.com/cs/document/109748872/
The “Message Queue Telemetry Transport” is a simply structured binary Publish/ Subscribe protocol on TCP/IP level. It is suitable for messaging between devices with minimum functionality and for transmission via unreliable networks with low bandwith and high latency. With these characteristics, MQTT plays a vital role for the IoT and in M2M communication.

The application example provides you with a function block for the SIMATIC S7-1500. The “LMqtt_Publisher” function block integrates the MQTT client function and allows you to transmit MQTT messages to a broker (publisher role). In this, the communication can be secured via a TLS connection.
MQTT Publisher for SIMATIC S7-1500 CPU MQTT Publisher for SIMATIC S7-1500 CPU

MQTT Publisher for SIMATIC S7-1500 CPU MQTT Publisher for SIMATIC S7-1500 CPU

The MQTT protocol stands out with the following characteristics:
Light-weight protocol with low transport overhead
Minimum requirement for network bandwith thanks to push mechanism
Function for re-connecting after disconnection
Re-sending messages after disconnection
Mechanism for notifying interested parties after an unpredicted disconnection of a client
Simple use and implementation thanks to a small set of commands
Quality of Service (QoS level) with different reliability levels for the message delivery
Optional encryption of messages via SSL/TLS
Authentication of publishers and subscribers via user name and password
Documentation and project example
https://support.industry.siemens.com/cs/attachments/109748872/109748872_MqttClient_Publish_CODE.zip
https://support.industry.siemens.com/cs/attachments/109748872/109748872_MqttClient_Publish_DOKU_en.pdf