Multi-Tech Systems MT4X56USB manual Registers, Register Unit Range Default Description

Chapter 4 - AT Commands, S-Registers and Result Codes

S-Registers

Certain modem values, or parameters, are stored in memory locations called S-registers. Use the S command to read or to alter the contents of S-registers (see previous section).

Register	Unit	Range	Default	Description
S0	1 ring	0, 1–255	1	Sets the number of rings until the modem answers. ATS0=0
				disables autoanswer completely.
S1	1 ring	0–255	0	Counts the rings that have occurred.
S2	decimal	0–127	43 (+) Sets ASCII code for the escape sequence character.
		128–255		Values greater than 127 disable escape.
S3	decimal	0–127	13 (^M) Sets the ASCII code for the carriage return character.
S4	decimal	0–127	10 (^J)	Sets the ASCII code for the line feed character.
S5	decimal	0–32	8 (^H)	Sets the ASCII code for the backspace character.
		33–127		Values greater than 32 disable backspace.
S6	seconds	2–65*	2*	Sets the time the modem waits after it goes off-hook before it
				begins to dial the telephone number.
S7	seconds	1–255*	50*	Sets the time the modem waits for a carrier signal before
				aborting a call. Also sets the wait for silence time for the @
				dial modifier.
S8	seconds	0–65	2	Sets the length of a pause caused by a comma character in
				a dialing command.
S9	decimal	0, 1–127	37 (%) Sets ASCII code for remote configuration escape character.
				S9=0 disables remote configuration.
S10	100 ms	1–254	20	Sets how long a carrier signal must be lost before the
				modem disconnects.
S11	1 ms 5	0–150*	95*	Sets spacing and duration of dialing tones.
S28	decimal	0, 1–255	1	0 disables, 1–255 enables V.34 modulation.
S30	1 minute	0, 1–255	0	Sets the length of time that the modem waits before
				disconnecting when no data is sent or received. A value of
				zero disables the timer. See also the \T command
S35	decimal	0–1	0	0 disables, 1 enables the V.25 data calling tone, which allows
				remote data/fax/voice discrimination.
S36	decimal	0–7	7	Specifies the action to take in the event of a negotiation
				failure when error control is selected. (See S48.)
S37	decimal	0–19	0	Sets the maximum V.34 “upstream” speed at which the
				modem attempts to connect.

0 = maximum modem speed

1 = reserved

2 = 1200/75 bps

3 = 300 bps

4 = reserved

5 = 1200 bps

6 = 2400 bps

7 = 4800 bps

8 = 7200 bps

9 = 9600 bps

10 = 12000 bps

11 = 14400 bps

12 = 16800 bps

13 = 19200 bps

14 = 21600 bps

15 = 24000 bps

16 = 26400 bps

17 = 28800 bps

18 = 31200 bps

19 = 33600 bps

* These values may be different outside North America.

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