HP Brio 81XX Online Manual page 50

Command
ATDn Tells the modem to go online and dial (automatic dialing). The following characters are authorized as parameters in the dialing sequence:
0 to 9 - For the telephone numbers.
P - For pulse dialing.
T - For touch tone dialing.
W - Tells modem to wait until it hears the line free signal (for use with branch exchanges).
S= n - Dials the number stored in register n (where n is a number from 0 to 3).
! - Calls exchange by flash.
^ - Switches off calling tone (during current dialing process).
;H - Terminates the dialing sequence and causes the modem to go offline after dialing so that you can conduct a normal voice
conversation. Example: ATDT123456;H.
, - Pauses the register (S8) time.
@ - Waits for 5 seconds of silence.
; - Stays in Command Mode after dialing.
ATEn Controls the Echo function, where n is either 0 or 1:
1 - Enables character echo so that modem commands appear on screen as they are entered.
0 - Disables the echo function.
ATHn Where n is either 0 or 1:
0 - Forces modem on-hook.
1 - Forces modem off-hook.
Description
4 Business Communications Options
Basic AT Commands
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