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Rev. G
16.
The index numbering is automatic, so starting with 0, you will start adding your
parameters to each index number by using the drop-down menu labeled
Source Data Pool. Navigate through this drop-down menu, then click the
desired parameter.
17.
You can also apply a gain/multiplier and offset to the value before it is sent to
the PLC as well as choose between signed and unsigned when relevant.
18.
Click the Add Parameter button when done.
19.
Repeat Steps 14 through 18 until you’ve added all groups and tags desired.
Click Commit All Changes in the left menu toward the bottom when done.
Section 8.7: MQTT Protocols
MQTT Theory of Operations
:
MQTT is a higher-level transport protocol for Publisher/Subscriber networks. However,
since it is a transport protocol it does not define a payload. All MQTT protocols require
there to be a publisher, a subscriber, and a broker. In most cases, the publisher
publishes one or more topics to the broker. One or more subscribers register a
subscription to one or more topics. Some things to keep in mind:
The publisher opens a connection to the broker only. It has no concept of what
the subscriber is doing.
The broker does not care about payload type or arrangement, but just passes
through whatever is wrapped in the transport layer.
The broker can be setup to buffer, but it can get very complicated, so most
brokers are in reliable proximity with the subscriber.
The subscriber does not really have a concept of the publisher, but only
subscribes to one or more topics.
