S23 - general bit mapped options status, S24 - sleep inactivity timer, S25 - delay to dtr off – Comtrol AT Commands User Manual
Page 140: S26 - rts to cts delay

AT Commands for CX81801/CX06833/CX81300/CX06827 Modems Reference Manual
Conexant
102184B
3-114
S27 - Bit Mapped Options Status
S27 indicates the status of command options.
Default: 73 (49h) (01001001b)
Bits 0,1,3 Synchronous/asynchronous selection (&Mn/&Qn)
3 1
0
0 0
0
= &M0 or &Q0
0 0
1
= &M1 or &Q1
0 1
0
= &M2 or &Q2
0 1
1
= &M3 or &Q3
1 0
0
= Reserved
1 0
1
= &Q5 (Default.)
1 1
0
= &Q6
Bit 2
Leased line control (&Ln)
0 =
Dial up line (&L0) (Default.)
Bits 4 - 5 Internal clock select (&Xn)
0 =
Internal clock (&X0) (Default.)
1 =
External clock (&X1)
2 =
Slave clock (&X2)
Bit 6
CCITT/Bell mode select (Bn)
0 =
CCITT mode (B0)
1 =
Bell mode (B1) (Default.)
Bit 7 - Reserved
S28 - Bit Mapped Options Status
S28 indicates bit mapped options status.
Default: 0
Bits 0 - 1 Reserved
Bit 2
Reserved (always 0).
Bits 3 - 4 Pulse dialing (&Pn)
0 =
39%-61% make/break ratio at 10 pulses per second (&P0)
(Default.)
1 =
33%-67% make/break ratio at 10 pulses per second (&P1)
2 =
39%-61% make/break ratio at 20 pulses per second (&P2)
3 =
33%-67% make/break ratio at 20 pulses per second (&P3)
Bit 5-7
Reserved