There are three sounds that can be produced by the A3:
a) one short beep at startup
b) two long beeps anytime when the Geiger tube inverter fails to produce 380V
c) three long beeps in case of network failure:
— for Ethernet this can be due to missing DHCP settings
— for Wifi this is due to being unable to connect to the AP (low signal, invalid credentials)
— for LoRaWAN, unable to join the gateway
— for GSM, unable to perform a GPRS attach