Appendix 2: AT Command Set
Perle 833IS User Guide 257
Subparameter
Definitions  <mod> = A decimal number which specifies the preferred modulation
(automode enabled) or the modulation (automode disabled) to use in originating
or answering a connection. The options are:
The modem may also automatically switch to another modulation (automode),
subject to the following constraints:
a. The modem may not be able to automatically switch from the current modulation
(specified by <mod>) to some other modulation. For example, there is no
standard way to automode from Bell 103 to V.23.
b. The DTE may disable automode operation (see <automode> below).
c. The DTE may constrain the range of modulations available by specifying the
<mod> Modulation Possible Rates (bps) 1Notes
V.21 300
V.22 1200
V.22 bis 2400 or 1200
V.23 1200 See Note 2
V.32 9600 or 4800
 V.32 bis 14400, 12000, 9600, 7200, or 4800
 V.34 33600, 31200, 28800, 26400, 24000,
21600, 19200, 16800, 14400, 12000,
9600, 7200, 4800, or 2400
 K56flex 56000, 54000, 52000, 50000, 48000,
46000, 44000, 42000, 40000, 38000,
36000, 34000, 32000
[default]
 V.90 56000, 54667, 53333, 52000, 50667,
49333, 48000, 46667, 45333, 42667,
41333, 40000, 38667, 37333, 36000,
34667, 33333, 32000, 30667, 29333,
28000
 Bell 103 300
 Bell 212 1200
Notes:
1. See optional <automode>, <min_rate>, and <max_rate> subparameters.
2. For V.23, originating modes transmit at 75 bps and receive at 1200 bps; answering modes transmit
at 1200bps and receive at 75 bps. The rate is always specified as 1200 bps.