Introduction to AT commands - Hologram Documentation

? (read): Query current value, e.g., AT+CFUN? .
= (set): Set value, e.g., AT+CFUN=1 .
=? (test): Show supported options, e.g., AT+COPS=? .

AT command basics

AT (Attention) commands are used to communicate with cellular modems via a serial interface.

Connect to your modem

Use a terminal (e.g., Screen, Tera Term, PuTTY, GTKTerm) to open the modem’s serial port. Send AT and expect OK.

Understand operators

Note: You can also run the automated diagnostics script if preferred.