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RonHel5-Regular Member
5-Regular Member
August 15, 2023
Solved

Getting warnings using MQTT Client in KepserverEX 6.12 connected to EMQX 4.4.1 broker $SYS Topic

  • August 15, 2023
  • 1 reply
  • 2016 views

Hi all

i am getting these warning every 30second when connected to broker in $SYS/ Topic


2023-08-15 13:59:16 Warning MQTT Client Unexpected token found while looking for the end of the MQTT payload. | Channel = 'MQTT_****LAB01', Topic = '$SYS/brokers/emqx@****lab01/version', Line = 1, Col = 2.

 

Values are ok

RH_9464494_0-1692102226858.png

Is there a way to use $SYS Topics and avoid these warnings

 

"Normal" Topics seems to work without warnings.

 

//Ronnie

 

 

 

 

Best answer by cmorehead

@RH_01_9464494,

 

Using wild cards as the first character in a topic does not generate topics that start with ‘$’. This standard MQTT behavior is described in the specification. To get data from ‘$SYS’, set the topic to ‘$SYS/#’. Please take a look at the page in the manual in the following link that covers this: https://www.ptc.com/store/-/media/kepware-store/en/manuals/mqtt-client-manual.pdf#page=12

 

Thanks,

*Chris

 

 

1 reply

C
cmorehead13-AquamarineAnswer
13-Aquamarine
August 17, 2023

@RH_01_9464494,

 

Using wild cards as the first character in a topic does not generate topics that start with ‘$’. This standard MQTT behavior is described in the specification. To get data from ‘$SYS’, set the topic to ‘$SYS/#’. Please take a look at the page in the manual in the following link that covers this: https://www.ptc.com/store/-/media/kepware-store/en/manuals/mqtt-client-manual.pdf#page=12

 

Thanks,

*Chris

 

 

    R
    RonHel5-Regular MemberAuthor
    5-Regular Member
    August 21, 2023

    Thank you for answer! It was however already set as suggested ‘$SYS/#’

    I might miss something here! 

     

    Here is my configuration.

    Device/Tag Generation/Topic= $SYS/#

    Tag Address = $SYS/brokers/emqx@lab01/version#Payload

    Still getting warnings

     

    I have done some other tests to a mosquitto broker and then it works without any warnings.

     

    Thanks, Ronnie

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