User Manual
UG_2901CE_027 73M29 01CE AT Command User Guide
Rev. 2.0 27
bit 5 S63 bit 1 is selected tone of precise busy (Default).
bit 6 S63 bit 2 is selected tone of precise busy .
bit 7 S63 bit 3 is selected tone of precise busy (Default).
Note: See calling code table on use.
4.4.21 S20 – Call Progress Tones Detect Type
(Default = 11h)
Busy Dialtone
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Bits 3/7 Bits 2/6 Bits 1/5 Bits 0/4 Function
0 0 0 1 Detect Imprecise tones ONLY (default).
0 0 1 0 Detect All Precise tones ONLY.
0 1 0 0 Detect Any of the Precise tones.
4.4.22 S21 – Bit Mapped Register
(Default = 01h)
Bit 0 0 = Keypress abort disable.
1 = Keypress abort enable (Default).
Bit 1 0 = Use debounce carrier detect (Default).
1 = Use raw carrier detect (set by C2 command).
Bit 2 0 = Disable V.23 turnaround via DTR toggle (Default).
1 = Enable V.23 turnaround via DTR toggle (set by R4 command).
Bit 4 Bit 3 Function: DTR Control
0 0
Modem ignores DTR (Default) (R0)
0 1
Modem assumes the Command State when DTR transitions from
ON to OFF (R1).
1 0
Modem goes on hook, disables Auto Answer and assumes the
Command State when DTR transitions from ON to OFF (Auto
Answer can be enabled by transitioning DTR from OFF to ON) (R2).
1 1
Modem is reset when DTR transitions from ON to OFF (R3).
Bit 5 0 = CD always ON (equivalent to C0 command) (Default).
1 = CD ON indicates the presence of CD (equivalent to C1 command).
Bit 6 0 = No RTS / CTS DTE flow control (equivalent to K3) (Default).
1 = RTS / CTS DTE flow control.
Bit 7 0 = No XON / XOFF DTE flow control (equivalent to K4)(Default).
1 = XON / XOFF DTE flow control.