Once the device receives a UDP packet which does not have payload (which are commonly used as keepalive) the socket locks up: it can no longer receive new packets.
Firmware revision: L0.0.00.00.05.06 [Feb 03 2018 13:00:41]
I tried sending an empty UDP package using: AT+USOST=0,"IP",PORT, 0, "", but it didn't really like the empty data. I got a generic CME ERROR: OPERATION NOT ALLOWED. How have you managed to send an empty UDP packet?
@M.Bend I think he means sending a message to the device, not sending from it.Sending an empty string, from the device, is not possible.
Thanks, explains. Reading is hard on the early monday morning.