Specifications

Si2404
34 Rev. 0.91
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 14 summarizes the S-register set.
Table 14. S-Register Description
Definition
S-Register
(Decimal)
Function Default
(Decimal)
Range Units
0 Automatic answer—Number of rings the Si2404 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 Si2404
waits before blind dialing. Only applicable if blind dial-
ing is enabled (X0, X1, X3).
02 0–255 seconds
7 Carrier wait timer—Number of seconds the Si2404
waits for carrier before timing out. This register also
sets the number of seconds the modem waits for ring-
back 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 Si2404 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 Si2404 to rec-
ognize 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