Malfunction of EHS5-US related to simcard | Thales IoT Developer Community
January 23, 2019 - 3:04pm, 4918 views
I have the following problem with an EHS5-US module:
I have thousands of EHS5-USs running and suddenly 1 of them stops working after months of doing it correctly. The symptom is verified because the LED of the EHS5 is always off (command AT ^ SLED = 2) and there is no further communication with the module.
Resetting or turn off the power supply (20 seconds without VBat and due to the capacitor in VBat the voltage drops to 1.2V approx.) does not solve the problem.
If, when replacing the module with a new one (tested in the factory), the same simcard that was in the faulty module is used, the same fault is presented in the new module. It is the "simcard of death". If the simcard is removed both modules work normally.
If I reuse the "simcard of death" in the first module that failed now works normally. It seems that using the simcard in another module (which also failed) fixes the problem (this behavior is repeated in all cases).
Can the simcard cause a malfunction in the EHS5-US module?
Where can I find a list of the bugs that the EHS5-US has or had in previous versions?
The EHS5-US reports: