Specifications

August 26, 2004 TechMemo 01-0011B
14 of 24
US Robotics V.90 and V.92 modem reference
DIP switches
DIP
switch
Setting
(UP = off,
DOWN = on)
AT
command
equivalent
Function
(US Robotics settings in italics. Adaptive settings in bold.)
1
UP &D0
Normal DTR (Data Terminal Ready) operations — computer must provide DTR signal for the modem
to accept commands. Dropping the DTR terminates a call.
DOWN &D1 DTR override — modem ignores DTR signal.
2
UP V1 Use verbal result codes.
DOWN V0 Use numeric result codes.
3
UP Q1 Suppress result codes.
DOWN Q0 Enable result codes.
4
UP E1 Local echo on — display keyboard commands.
DOWN E0 Local echo off
5
UP
S0 = 1
(or greater)
Auto answer on — modem will answer calls on the first ring (or the number of rings set in register
S0). Also, modem AA LED will be on.
DOWN S0 = 0 Auto answer off — modem will not answer calls. Modem AA LED will be off.
6
UP &C1
Normal CD (Carrier Detect) operations — modem sends CD signal when it connects with another
modem. Modem drops CD on disconnect.
DOWN &C0 Carrier detect override — CD always on. Modem CD LED will always be on.
7
UP
—
On modem powerup, load Yn template (default = Y0).
DOWN On modem powerup, load &F0 generic template settings.
8
UP
—
Modem will not recognize AT commands (dumb mode).
DOWN Modem will recognize AT commands (smart mode).