Door and Acc attributes not processed for tracker devices sending two messages instead of one

Good afternoon to all,

We're observing that Coban trackers report messages in two different ways. We see the behavior both within TK103 trackers, and with TK405.

The "normal" situation is a tracker which sends 1 message to the server:

2024-12-06 09:10:25  INFO: [T1e46a471: gps103 < 31.161.206.80] 696d65693a3836343138303033373434373531382c747261636b65722c3234313230363136313032352c2c462c3038313032322e3030302c412c353232312e303739342c4e2c30303435372e323832312c452c302e30302c302c2c302c302c302e3030252c2c3b

Which decodes to imei:864180037447518,tracker,241206161025,,F,081022.000,A,5221.0794,N,00457.2821,E,0.00,0,,0,0,0.00%,,;

With these devices, we also get 1 response by SMS:

But we also observe some TK103 devices sending two messages:

 INFO: [Td11a7679: gps103 < 89.200.40.109] 696d65693a3836343138303033373433313138312c747261636b65722c3234313230363136313031392c2c462c3038313031352e3030302c412c353232312e303238342c4e2c30303435372e333039362c452c302e30302c302c2c302c302c30

which decodes to imei:864180037431181,tracker,241206161019,,F,081015.000,A,5221.0284,N,00457.3096,E,0.00,0,,0,0,0

and

2024-12-06 09:10:20  INFO: [Td11a7679: gps103 < 89.200.40.109] 2e3030252c2c3b

which decodes to .00%,,;

These devices also send two replies per SMS:

The issue with the latter is that Traccar does not report the value of the Door and Acc attribute. These remain No, even if according to the sms reply the tracker reports yes.

So it seems that some devices send the data in two separate consequtive messages to the server instead of in 1 message, and as a result of that, some data is not correctly processed.

Would there be a way to correctly process the data such that Door and Acc attributes are filled with data for the devices who send two messages? Approximately 40 % of the Coban devices send one message and the remaining 60 % send two messages.

It's normal that TCP packets can be broken down to smaller ones. It doesn't mean they are sent by device like this. And it doesn't mean they're not processed correctly.

Dear Anton. Thank you for your swift reply. Good to know it's completely normal behavior then.
Nevertheless, we consistently observe that a) for all trackers which sent replies by 2 sms instead of 1, b) the messages are split in 2 in the server log, and c) the values for Door and Acc are not shown, although the SMS report shows they're on/true.

Herewith an example. This is the GPS response of one tracker, showing Acc and Door ON.

Same time, this is the message from the log:

2024-12-06 17:08:54  INFO: [T07d354ea: gps103 < 31.161.190.55] 696d65693a3836343839353033363332333838372c747261636b65722c3234313230363136303835322c2c462c3136303835322e3030302c412c353232302e39353336352c4e2c30303435372e34373831342c452c302e30302c3332392e3830
2024-12-06 17:08:54  INFO: [T07d354ea: gps103 < 31.161.190.55] 3b
2024-12-06 17:08:54  INFO: [T07d354ea] id: 864895036323887, time: 2024-12-06 17:08:52, lat: 52.34923, lon: 4.95797, course: 329.8

--> decoding to imei:864895036323887,tracker,241206160852,,F,160852.000,A,5220.95365,N,00457.47814,E,0.00,329.80

And this is the result in Traccar:

Again, the fact that message is split is completely irrelevant for decoding.

Thank you Anton, that I understood from your last reply. Do you maybe see any other reason why the Door and Acc attributes are not showing?

I'm not even sure it's supported in the first place.

All trackers which respons within 1 message instead of 2 (although that's not the cause of the issue) do send those values. I would then assume it's a firmware thing on the tracker itself?

Could be a firmware or configuration.