I got a new sim and this solved the problem.
It’s working again.
Is there a time limit on the sim’s?

Well, i would be interested in this option. Provided i get my system working again.
See other posts.

The problem here is that i had a working system, no problems at all. Went to the location were it should be installed, to try if it worked. Again no problem.
Came home, switched it one and have had no connection since.
I am using a sim card i got last year. Now i ordered a new one to see if that’s the problem.

Meanwhile i tried reboot, did the whole startup procedure from the doc’s again. Nothing helped.

I am using the NB-IOT Bee version from Dragino.
(http://www.dragino.com/products/nb-iot/item/132-nb-iot-bee.html)

I am creating a guarding system for a lithium battery. When they overload, or when the charging stops it would be nice to receive a direct warning. That’s where SMS could come in handy.

@stefan-de-lange Read it now. There might be an aswer there, but i don’t see how i could change this.
But still i believe it is technically possible to receive a downlink without an uplink first. The network knows the device is alive, and has a message waiting. So why should there be an uplink first.
I am hoping t-mobile will tell me (us) that it will make this possible soon.
thank you for your time.

After a nice successfull period of testing my NB-IoT Bee module lost signal.
After a restart off the computer the AT+CSQ command returns 99,99
It’s been day’s now without any clue about the rrason why.
Has anyone a possible answer?

thank you for any help.

My topic Downlink Response has lost it’s reason to live.
But i still want to know about the Downlink funtion. Will there be a possibility for automatic receiving a downlink, whitout the need for a Uplink first.
I will be sending an uplink every hour and it would be a waste of resources to start polling every 5 minutes.

Found the problem already, you have to read the message’s. Then the next message will arrive.

I got the downlink working as far as the response :
{“requestId”:“33b82455-96ad-49c8-b6a2-6c4101f1fafc”,“msg”:“Accepted”,“code”:1002}

But although there were several uplinks from my device after that, still no message received.
How long can it take before there is a response.
And will it always be required to first start an uplink. That would mean i have to start polling the network.

In the documentation from Quectel there’s the option for sending an SMS message directly from my device.
4.4. AT+CMGS Send SMS Message.
Can this be done through the T-Mobile network?