store attribute value

hello everyone, I'm using the osmand protocol and sending values ​​to a new attribute I created... the problem is that when my device restarts, it resets the variable's value and forwards it to the server... I need the value to continue to always increase. I tried with calculated attributes but still I couldn't. Can anyone with experience in this help me?

It's not possible with computed attributes.

Well... maybe me explaining my need, maybe they will point me in some direction...

I have a vehicle with two types of fuel (fuel1 and fuel2)

I already have a tracker on this vehicle measuring the "level in the tank" of fuel 1 (main)...

however, in the second tracker (the one I'm using the osmand protocol) I need to measure the fuel2, but instead of measuring the level in the tank what I need is "measure the fluidity or flow".

I tried using the native attribute "fuel" but the problem is when my device restarts... it ends up restarting this consumption from scratch...

Within what the software has today, is there any usability similar to my attempt?

Same answer.

Thanks.

May be, if I understand you right, you can write a proxy.
He collects the data from both tracker, combine this and send
the data in one connection with osmand to traccar.

It is more ore less work, depending how are your needs
for synchronized times.