S2 changes the escape character (from + to 0xFF) S12 changes the escape sequence delay https://en.wikipedia.org/wiki/Hayes_AT_command_set#Modem_S_register_def

S2 changes the escape character (from + to 0xFF) S12 changes the escape sequence delay https://en.wikipedia.org/wiki/Hayes_AT_command_set#Modem_S_register_definitions https://en.wikipedia.org/wiki/Hayes_AT_command_set#Modem_S_r...