Description:
Sometimes tacho data download might end up with a communication or authorization error, and after checking the tacho state it might sometimes display state 1 and with the next SMS - state 0.
This article describes possible reasons and what additionally can be checked to identify the root cause.
Common causes:
A possible reason for this behavior is that in parallel with our device, another third-party device is communicating with the tachograph.
Please note that this article is mostly related to:
TCO4 HCV devices;
HCV5/HCV5 lite devices with FW 00.06.00.00 build 40.xx or older, after FW build 41.xx our devices are capable of communicating with tachograph even if there are third-party devices installed.
Required information:
Device logs | The collected device logs might confirm if there is another device is connected, if client uses TT2 the logs preferably needs to be collected with Test FW which can be found here: FW archive |
Info regarding any other devices in the vehicle | You can also try to ask the client if he checked the vehicle regarding any third-party devices which could be communicating with tachograph. |
Recommended tools:
Application | Download link |
Notepad or Notepad++ | In order to check device logs Notepad++ might be more helpful: |
Steps:
When logs are collected please try to look in the logs for the following message:
Pack->MayNotExpect
As this message says our device received a packet from a tachograph that was not requested, such cases most times can occur only if the third-party device is also communicating with the tachograph.
If you see such message, in this case please ask the customer to double check if there are no third party devices installed in the vehicle.