ICP DAS USA ET-2217CI, Руководство пользователя

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ET-2200 Series Ethernet I/O Modules
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4.13 MQTT
Note: The function is available for AIO and DIO modules.
Chapter DIO AIO
4.13.1 Connectivity Settings
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4.13.2 Publication Settings
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4.13.3 Publication Settings
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4.14 MQTT-DO
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4.15 MQTT-DI
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4.16 MQTT-AI -
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MQTT is a Client Server Publish/Subscribe messaging transport protocol. It is simple, light-weight,
and open, and is designed to be easy to implement. These characteristics make it ideal for use in
many situations, including constrained environments such as for communication in Machine-to-
Machine (M2M) and Internet of Things (IoT) contexts where a small code footprint is required and/or
network bandwidth is at a premium.
MQTT is a protocol consisting of a Publish/Subscribe mechanism where the Client only needs to
know the IP address for the Broker. The Broker then acts as a central location to handle the sending
and receiving of all messages between a Publisher and a Subscriber. The Publisher is the entity that
publishes the topic and message , the Subscriber is the entity that receives the updated messages
from the Broker. When the Publisher updates a message related to a specific-topic, it is transmitted
to the Broker, which will then send the message to all Subscribers that have subscribed to that
particular topic. Neither the Publisher and nor the Subscriber need to know the status of the other.
AI Module
DI/DO Module