Specifications
Si2457/34/15/04
Rev. 1.3 41
5. S-Registers
The S command allows reading (Sn?) or writing (Sn = x) the S-registers. The S-registers store values for functions
that typically are rarely changed, such as timers or counters, and the ASCII values of control characters, such as
carriage return. Table 13 summarizes the S-register set.
Table 13. S-Register Description
Definition
S-Register
(Decimal)
Function Default
(Decimal)
Range Units
0 Automatic answer—Number of rings the Si2457/34/15/
04 must detect before answering a call. 0 disables auto
answer.
0 0–255 Rings
1 Ring counter. 0 0–255 Rings
2 ESC code character. 43 (+) 0–255 ASCII
3 Carriage return character. 13 (CR) 0–255 ASCII
4 Linefeed character. 10 (LF) 0–255 ASCII
5 Backspace character. 08 (BS) 0–255 ASCII
6 Dial tone wait timer—Number of seconds the Si2457/
34/15/04 waits before blind dialing. Only applicable if
blind dialing is enabled (X0, X1, X3).
02 0–255 seconds
7 Carrier wait timer—Number of seconds the Si2457/34/
15/04 waits for carrier before timing out. This register
also sets the number of seconds the modem waits for
ringback when originating a call before hanging up.
This register also sets the number of seconds the
answer tone will continue while using the AT
*
Y2A
command.
80 0–255 seconds
8 Dial pause timer for , and < dial command modifiers. 02 0–255 seconds
9 Carrier presence timer—Time after a loss of carrier
that a carrier must be detected before reactivating
DCD
. S9 is referred to as “carrier loss debounce time.”
06 1–255 0.1 second
10 Carrier loss timer—Time the carrier must be lost before
the Si2457/34/15/04 disconnects. Setting 255 disables
disconnect entirely. If S10 is less than S9, even a
momentary loss of carrier causes a disconnect.
14 1–255 0.1 second
12 Escape code guard timer—Minimum guard time
required before and after “+++” for the Si2457/34/15/
04 to recognize a valid escape sequence.
50 1–255 0.02 second
14 Wait for dial tone delay value (in relation to the W dial
modifier). Starts when “W” is executed in the dial
string.
12 0–255 seconds