ICP DAS USA U-7500 Series, User Manual

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OPC UA I/O Series User Manual V4.0 – ICP DAS
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The setting parameters for Both enable or disable the JSON Format:
MQTT Setting > Client Setting - Publish & Subscribe
Publish Topic The topic of sending data / publishing message.
Publish QoS The publish Qos (Quality of Service) levels. Default: 2
0: Delivering a message at most once.
1: Delivering a message at least once.
2: Delivering a message at exactly once.
Subscribe Topic The topic of receiving data / subscribing message. It can copy the Publish
Topic of linked device.
Subscribe QoS The subscribe Qos (Quality of Service) levels. Default: 2
0: Delivering a message at most once.
1: Delivering a message at least once.
2: Delivering a message at exactly once.
Retain Set up if the Broker retains the message.
Save Click to save the setting of this page.
When Enable JSON
format , it will pack
all I/O point values
into a JSON string,
and then send the
JSON string as a
message or
subscribe JSON
string to get all I/O
values back at one
time. (Refer to
Appendix B )
When Disable JSON
format , it will
publish or subscribe
the message in
singly (Point-to-
point). User needs to
set each I/O point.
5. If Broker retains the message
1. Topic for sending JSON string
2. QoS for sending JSON string
3. Topic for reading JSON string
4. QoS for reading JSON string
1. Topic for sending DO0 value
3. Topic for reading DO0 value