@Stefan-de-Lange I dont have the upgrade yet but willupgrade as soon as I do!, in the meantime I read somewhere that It could work if you enable a sim pin. And that works!

Thanks I think I tried these already but could not get it to work. what terminal program did you use? And maybe other things that are of importance?

@Crowdsourcer what instructions did you use, for me serialpassthrough did not work

@Stefan-de-Lange if you want to measure sleep current of the mkrnb1500 I would turn of all other peripherals. And I agree that psm might give better overall results if you send often but when you send once in a while (like I do) I think turning it off is more power efficient? The clock speed was just an example (arduino code is meant to be interchangeable between mcus so might not be optimal)

@Crowdsourcer do you turn off the sara module before sleep?

@Crowdsourcer the sleep current on the mkrfox1200 boards Ive used vary from 80 to +/- 180 uA but it very much depends on what pins you use. ( mkrfox1200 uses the -DVERY_LOW_POWER option in boards.txt)
@Stefan-de-Lange I dont think its only the board thats not optimised, but also the current arduino implementation. for example you could run the samd21 at lower speed.

@Crowdsourcer I use the portable version of the arduino ide so I can have multiple installations with different settings and/or library/board versions. This may help you not having to reinstall after changing boards.txt (you can just make a copy of the folder before making changes)

I think it is 1600 bytes but that is per message you can always send more messages. I dont know if Tmobile supports non hex string format. Maybe first get it to work with hex and if that works try binary?

Whats the reason you dont want to send the data as Hexstring?

I send my values as Hex values so only 0-9A-F characters are sent

sorry I think I was not clear. What Imeant to ask is if you get the correct number at your application server. Maybe you can set the application server to winhook.info to test?