subscribe to our Youtube


14455 questions

17168 answers


0 members

We are migrating to our new platform at Moving forward, you can continue discussions on this new platform. This current platform will be temporarily maintained for reference purposes.
+1 vote
318 views 0 comments
by anonymous


We've tried to configure our Teltonika RUT955 to transmit our modbus requests to Azure. We've found, after some troubleshooting, that the connection string we receive from Microsoft is too long to enter in the RUT configuration. This string is limited to 150 characters. We believe this is a problem that is likely to be encountered by others. Is this something that can be adapted?

version: RUT9_R_00.07.00

Kind regards,


2 Answers

0 votes
by anonymous

Thank you for the information, could you try to check the RUT9XX_R_00.06.08.3 firmware version if that is the case too? I will inform our RnD about this. Also, how many symbols does your connection string currently have?

0 votes
by anonymous


We are also facing this problem with TRB255 (TRB2_R_00.07.01.4

The limit in the input field "connection string" is 150, but there is absolute no error or warning.

If copy paste the connection string it look like everyting is OK, but if you then go to CLI and run azure_iothub you see this error :

Error: Time:Tue May  3 21:07:22 2022 File:azure_iothub-89127a34c09401562924edac77abb54030323484-2021-06-22/src/c-utility/src/base64.c Func:Base64_Decoder Line:201 Invalid length Base64 string!                                                                                                                         

Error: Time:Tue May  3 21:07:22 2022 File:azure_iothub-89127a34c09401562924edac77abb54030323484-2021-06-22/src/c-utility/src/sastoken.c Func:construct_sas_token Line:217 Unable to decode the key for generating the SAS.                                                                                                  

Error: Time:Tue May  3 21:07:22 

2022 File:azure_iothub-89127a34c09401562924edac77abb54030323484-2021-06-22/src/iothub_client/src/iothub_client_authorization.c Func:IoTHubClient_Auth_Get_SasToken Line:411 Failed creating sas_token                                                                                       

Error: Time:Tue May  3 21:07:22 2022 File:azure_iothub-89127a34c09401562924edac77abb54030323484-2021-06-22/src/iothub_client/src/iothubtransport_mqtt_common.c Func:SendMqttConnectMsg Line:2029 failure getting sas token from IoTHubClient_Auth_Get_SasToken. 

If you then deepdive into the source code (it is on microsoft gitbhub) you see that "sharedacceskey" value (last of the string that is cut off) must be MOD 4 dividable, which it is not.

We are using Azure IOT Central (which uses IOT Hub in the background) so we adjusted the DeviceId name so that the total connection string lenght is below 150. But I think the 150 is just some "number" that ever has been put in and should be increased in the next firmware update (+ a warning message if above the limit)

I also "data to server" has to bug because there we also are not able to make a connection to Azure IOT