Maxim Integrated 73M2901CE AT Command - Manual (Page 30)

73M2901CE AT Command User Guide UG_2901CE_027
30 Rev. 2.0
Bit 5 0 = Disables guard tone generation (default).
1 = Enables guard tone generation.
Bit 6 0 = Disable V.23 turnaround.
1 = Enable V.23 turnaround.
Bit 7 Channel Set:
0 = Tx 1200 bps (Bell 202 and V.23 slave mode) (default).
1 = Rx 1200 bps (Bell 202 and V.23 master mode).
4.4.28 S27 – Call Progress Transmit Register
(Default = 0h)
Register S27 reflects the status of certain options. Default is 64. Register S27 is a bit mapped register
that behaves in the following manner when its bits are set:
Bit 0 Do not send DTE “0FFh” characters in pseudo sync (Y4 or &Q4) mode.
Bit 1 Transmit 1100 Hz when set to one.
Bit 2 Transmit 1300 Hz when set to one.
Bit 3 Transmit 2100 Hz when set to one.
Bit 4 Transmit 2225 Hz when set to one.
Bit 5 Disconnect Bit.
Bit 6 0 = CCITT V.22bis, V.22, V.21, V.23 (equivalent to B0) (Default).
1 = Bell103, Bell202, Bell212A (equivalent to B1).
Bit 7 Protocol Selection Done (read only).
Precedence is as follows:
Bit 1 takes precedence over bit 2, which takes precedence over bit 3, which in turn takes precedence over
bit 4.
4.4.29 S28 – Fast Connect, and Calling Tone Enable
(Default = 32h or 33h (reserve bit 0 toggles in idle state))
Register S28 reflects the status of various options. Register S28 is a bit mapped register whose bits are
defined as follows:
Bit 0 Reserved (SAGC Bit).
Bit 1 Reserved.
Bit 2 Demodulated FSK Microbit.
Bit 3 Sync Mode (set by Y1 or Y4).
Bit 4 Answer Tone Enable @ 1200 bps (default).
Bit 5 Billing Delay Enable @ 1200 bps (default).
Bit 6 400ms. Answer Tone @ 1200 bps.
Bit 7 0 = Calling Tone Disable (default).
1 = Calling Tone Enable.