4 S-Registers
CommPlete Communications Server 51
Reading and Assigning S-Register Values
Use the S command to assign a value to an S-register and to read an S-register’s current value.
To read an S-register value, in terminal mode, type S, the S-register number, and a question mark (?), and
press ENTER. For example, to display the value of register S7, type ATS7? and press ENTER. The answer will
appear as a three-digit decimal number (e.g.,
045
).
To assign a new value to an S-register, type S, the S-register number, an equals sign (=), and a decimal
number. Convert all ASCII characters to their decimal equivalents before entering them. S-register decimal
values are 0–127 for ASCII characters, and 0–255 for numeric values. To make the change permanent, use
the &W0 command.

Examples of Assigning Values

1. Let’s assume you want to have longer pauses caused by the comma in a dial command: five seconds

instead of two. Type ATS8=5 to assign 5 as the value for register S8. The modem will now pause five
seconds for every comma in a dial command.

2. Or let’s assume that you wish to configure the modem to answer incoming calls after the thirtieth

ring instead of after the first ring. To configure register S0
with a value of 30, type ATS0=30 and
press ENTER.

3. Or let’s say you are calling long distance to another country code, and it is t aking a long time to

connect. The register S7
(abort timer) factory default setting of 45 seconds is insufficient; the abort
timer times out and cancels the call before a connection is made. To change the S7
value to 55
seconds, type ATS7=55 and press ENTER. Now, after dialing, the modem allows 10 more seconds for
a carrier signal before aborting the call. The additional 10 seconds sho uld provide enough time for
international calls.

Examples of Reading Values

1. To verify that you entered the value correctly in the preceding examples, type ATS8? and press

ENTER in the first example, ATS0? in the second example, and ATS2? in the third example. You
should receive the responses
005
,
030
, and
055
, respectively.

2. When configuring S-registers, it is a good practice to include the verif ication read command in the

same command string as the configuration assignment command. In the three preceding examples,
type ATS8=5S8?,
ATS0=30S3?, and ATS7=55S7?, respectively.
AT Commands that Affect S-Registers
For maximum throughput, the MT3334HD8’s default configuration is for originating a call to another
33,600 bps modem that supports error correction, data compression, and flow cont rol. If the receiving
modem is not compatible, the MT3334HD8 can match any ITU-T or Bell standar d modem (but not
proprietary protocols).
If you require a different configuration for your application, for example, if you want to use an
MT3334HD8 modem strictly as an auto answering device, or for service t hat does not support error
correction, you can selectively change the command parameters and S-register va lues in active memory and
save the new values by using the &W command.