MultiModemDSVD User Guide

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 before the mo-

 

 

 

 

dem answers. ATS0=0 disables autoan-

 

 

 

 

swer 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

 

 

128–255

 

character. 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 char-

 

 

 

 

acter.

S5

decimal

0–32

8 (^H)

Sets the ASCII code for the backspace

 

 

33–127

 

character. Values greater than 32 disable

 

 

 

 

backspace.

S6

seconds

2–255

2

Sets the time the modem waits after it goes

 

 

 

 

off-hook before it begins to dial the tele-

 

 

 

 

phone 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 modifi-

 

 

 

 

er, and the time the modem waits for the

 

 

 

 

dial tone after encountering W in the dial

 

 

 

 

string.

S8

seconds

0–255

2

Sets the length of a pause caused by a

 

 

 

 

comma character in a dialing command.

S9

100 ms

1–255

6

Sets the time, in tenths of a second, that

 

 

 

 

the carrier must be present before the mo-

 

 

 

 

dem considers it valid.

S10

100 ms

1–255

14

Sets how long a carrier signal must be lost

 

 

 

 

before the modem disconnects.

S11

1 ms

50–255

95

Sets spacing and duration of dialing tones.

S12

20 ms

0–255

50

Defines the maximum period, in fiftieths

 

 

 

 

of second, allowed between receipt of the

last character of the three escape character sequence from the computer and the sending of the OK result code to the computer. (Escape code guard time).

Multi-Tech Systems, Inc.

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