I have the UE910 cellular module from Telit. I have manufactured a PCB containing the module but it's not working (power is reaching it but serial program not communicating with the tx and rx pins). I know now that the problem maybe is that I left 2 pins ("On/OFF" and "HW_Shutdown") unconnected even though the datasheet recommends connecting them.
I attached some screenshots from the datasheet.
It is written however that the "HW_shutddown" pin can be left floating as it is internally pulled up so it might be the "ON/OFF" one that need to be connected. Can you help me state the functionality of that pin? Do you think it is the reason why the module is not working?