MQ-7200M User Manual, version 1.0.1
Page: 38
In the publisher/subscriber model, once subscribe to a topic (or I/O channel), the subscriber can
receive the information (status) related to that topic. The publisher can periodically send its
content to all subscribers of the topic, or whenever there is new information available.
Publications
The I/O status can be published to topics based on either a time-driven or event-driven approach.
Time-driven:
The I/O status is regularly published at specific intervals (10-600 seconds), which can
be configured in the "
Periodic publish interval (Sec)
" field.
Event-driven: The I/O status is published when specific conditions are met. The user can learn how
to configure the conditions in the subsequent content.
QoS (Quality of Service)
0 – At most once:
Send the message only once
1 – At least once:
Send the message at least once
2 – Exactly once:
Make sure the message is delivered
