User guide

8
ATQn Quiet Results Codes Control
This command enables or disables the sending of result codes to the
DTE according to the parameter supplied. The parameter value, if valid,
is written to S14 bit 2.
ATQ0 Enables result codes to the DTE (Default.)
ATQ1 Disables result codes to the DTE.
AT+MS Commands Select Modulation
This extended-format command selects the modulation and, optionally enables
or disables auto mode, specifies the lowest and highest connection rates, selects
M-Law or A-Law codec type, and enables or disables robbed bit signaling
generation (server modem) or detection (client modem) using one to five sub
parameters. The command format is:
+MS= <mod> [,[<automode>][,[<min_rate>][,[<max_rate>][,[<x_law>][,[<
rb_signaling>]]]]]]<CR>
Notes:
1. For 14400 bps and lower speeds, the Nn command and S37 register can
alternatively be used, in which case the +MS sub parameters will be modified to
reflect the Nn and S37=x settings. Use of the Nn and S37=x commands is not
recommended but is provided for compatibility with existing communication
software.
Some advanced Rockwell HCF commands
ATZ- This command resets the modem to the stored settings. If the settings have
been changed by software or changed manually, this INIT string may not work
correctly. If you want to custom configure your stored profiles, we suggest that you
always start out with an AT&F&C1 before customizing other commands. This string
will reset the modem to the factory defaults as well as reset some other basic
settings.
If modem performance suffers after modifying settings, send the default AT string
(
AT&F;+MS=V32,1, 1200, 9600,1200,9600;-SEC=1,12;\N2;)M1;X0&W ) to the
modem.
Performance issues
To get optimum performance from your CDS-90XX MODEM, the phone line quality
over which you are transmitting and receiving must be reliable and relatively free of
"noise". If you have very noisy lines you may be able to get a better connection by
forcing the modem to connect at a lower speed. Refer to the AT+MS command.
Limiting the Modem’s top speed
If you experience problems connecting to slower modems (2400 or 1200bps), you
may need to instruct your modem to limit the attempted top speed to something less
than 19,200bps, due to the line noise in your area. If you don't, you may experience
noise interference and a "NO CARRIER" message will be displayed.