MQTT how to filter topic?

[KevinVt]

Dear Mikhail，

I used MQTT client to subscribe one topic, like “report”, and can get data from MQTT server, but there is heartbeat data also use topic name “report”, so I can get two json message sometimes, the problems is when heartbeat message arrive, the channels data was set to null, I had used js sentence to filter data, but it did not work.

Is there any method to filter mqtt message, only get ‘real’ data and get rid of heartbeat data?

[Mikhail]

Hello,

In such situation, using JS is the right method. If it doesn’t work, provide more info.

[KevinVt]

Hello Mikhail,

Below 2 messages are got from MQTT Server, these topics are same, and type are different.
——————————————————————————–
Message1:
Topic=【report/allpoints】 msg=【{“saleid”:”10100001″,”gateid”:”10100001001″,”type”:”report”,”time”:”2023-06-01 13:10:00″,”sequence”:”22″,”source”:”da”,”meter”:[{“id”:”1″,”status”:”1″,”name”:”VrtDev1″,”values”:{“Pf”:”0.287000″,”Uab”:”391.900024″,”Ubc”:”392.300018″,”Uca”:”391.799988″,”Ia”:”0.400000″,”Ib”:”0.000000″,”Ic”:”0.400000″,”P”:”0.000000″,”Q”:”-0.160000″,”S”:”0.160000″,”EPI”:”2257.599854″,”EPE”:”10.800000″,”EQL”:”93.199997″,”EPIJ”:”0.000000″,”EPIF”:”0.000000″,”EPIP”:”0.000000″,”EPIG”:”0.000000″,”MDMINUTE”:”0.000000″,”MDHOUR”:”0.000000″,”MDDAY”:”0.000000″,”MDMONTH”:”0.000000″,”MD”:”0.000000″,”UaTHD”:”2.210000″,”UbTHD”:”2.510000″,”UcTHD”:”2.780000″,”IaTHD”:”0.000000″,”IbTHD”:”0.000000″,”IcTHD”:”0.000000″,”VUB”:”0.220000″,”CUB”:”100.000000″,”Pa”:”0.000000″,”Pb”:”0.000000″,”Pc”:”0.040000″,”IL”:”0.000000″,”EQC”:”980.000000″}}]}】 qos level= 【AtMostOnce】
Message2:
Topic=【report/allpoints】 msg=【{“saleid”:”10100001″,”gateid”:”10100001001″,”type”:”heart_beat”,”operation”:”notify”,”time”:”2023-06-01 13:10:07″}】 qos Level=【AtMostOnce】

I wrote below js code to filter the message,
—————-js code ————————

let data = JSON.parse(payload);

if (data.type == “report”) {

// set values
setValue(0, new Date(data.time).getTime());
setValue(1, data.sequence);

setValue(2, data.meter[0].values.Pf);
setValue(3, data.meter[0].values.Uab);
setValue(4, data.meter[0].values.Ubc);
setValue(5, data.meter[0].values.Uca);

}
else
{
log(“Ignore HearBeat Data…”);
}
————————————————

It can print the log “Ignore HearBeat Data…” when got message with type “heart_beat”, and at same time, all channels value were set to null.

I hope to get the channel value when got message with type of “report” and keep channel value unchange when got meesage with type “heart_beat”.

Hope you can understand what I said.

Thanks a lot.

[Mikhail]

Hello,

First of all, I would log some message if data.type == "report" to check whether that section is executed.

[Author]

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