Specifications

AN93
Rev. 0.8 27
The examples in Table 17 assume the modem is reset
to its default condition. Each command is followed by a
carriage return.
The modem has a 48-character buffer, which makes it
possible to enter multiple AT commands on a single
line. The multiple commands can be separated with
spaces or linefeed characters to improve readability.
Neither the AT nor the space (or linefeed characters)
are loaded into the buffer and are not included in the 48
characters. The command must end with a carriage
return character to instruct the modem to process the
command. The modem ignores command lines greater
than 48 characters and reports “ERROR”.
Table 18 shows examples of multiple AT commands on
a single line.
Consecutive U-Registers can be written in a single
command as “AT:Uaa,xxxx,yyyy,zzzz” where aa is the
first U-Register address in the three register
consecutive series. This command writes a value of
xxxx to Uaa, yyyy to Uaa+1, and zzzz to Uaa+2.
Additional consecutive values may be written up to the
48 character limit.
Caution: Some U-Register addresses are reserved for
internal use and are not available. Consequently, there
are gaps in the addresses of available U-Registers.
Writing to reserved registers can cause unpredictable
results. Be certain the U-Register addresses written
with a consecutive write command have consecutive
addresses. Only one :U or :R command is allowed per
AT command line.
If a command line has multiple commands, there can be
only one :U or :R command, and it must be the last
command in the string. For example,
ATS0=3M1X1:U42,0022.
Table 17. Command Examples
Command Result Comment
AT$ E = 001 Configuration status of basic
AT commands.
M=000
Q = 000
V=001
X=004
Y=000
AT&$ &D = 001
&G = 017
Configuration of &AT
commands.
&H = 000
(Si2457)
&P = 000
ATS2? 043 S-Register 2 value—Escape
code character (+).
AT:R2C 00A0 Value stored in register U2C.
Table 18. Multiple AT Commands on a
Single Line
Command Result
ATS0=4M1X1<CR> The modem auto-answers on
the fourth ring. The speaker
is on during dial and hand-
shake only. Blind dialing is
enabled.
AT S0=4 M1 X1 <CR> Same as above (spaces do
not matter).
ATS0=4<CR> Same as above.
ATM1<CR>
ATX1<CR>
Table 19. Consecutive U-Register Writes on a
Single Line
Command Result
AT:U00,0078,67EF,C4FA 0x0078 written to U00
0x67EF written to U01
0xC4FA written to U02
Table 18. Multiple AT Commands on a
Single Line
Command Result