I have SODAQ SARA R412M Board and we are using DU NBIOT sim . I tried updating the firmware, but unable to update it. Every time it is showing same message of unable to connect to the board. I followed the instruction carefully for the updating firmware.
Also, when I give AT command of AT+UANTR=0 result is showing as “+UANTR: 0,-1”. It shows that the antenna is open circuited. But we know that sim is working fine.
Please guide us to resolve these two problems ASAP.