Answering From Synchronous Mode; Auto-Answer; Manual Answer - ZyXEL Communications U-336R/RE User Manual

4. Manual dial: Set the modem to synchronous mode (&M1 or

Answering from Synchronous Mode

Auto-Answer

Set the modem to synchronous mode. Set the S-register S0 to equal
the number of rings before auto-answer occurs. Set it from the
terminal (if &M1 is set) using the asynchronous AT command, or
select the STATUS REGISTER menu to change the S0 value.

Manual Answer

Type ATA from the terminal (if &M1 is set).
&M3), then dial a number from a telephone set. When you hear
the answer tone, type ATD (if &M1 is set). The modem will go
into synchronous operation after connection.
Synchronous Mode Operation 33