Question

RUT230 report error 304 when I try to send SMS via AT+CMGS command.
Sending via gsmctl -S -s is Ok

Serial number 1000893109
Firmware version RUT2XX_R_00.01.14.4

Answer 1

I would check and make sure that your sim card is able to sent messages. If they are on the broadband plan they will need to have messaging services added.