3Com 000839-08 Manual page 166

Factory
Switch Setting Function
6 OFF Carrier Detect (CD) Override
OFF Modem sends CD signal when it connects with another modem, drops CD on disconnect
ON
7 OFF Power-on and ATZ Reset Software Defaults
OFF Loads Y or Y1 configuration from user-defined nonvolatile memory (NVRAM)
ON
8 ON AT Command Set Recognition
OFF Disables command recognition (Dumb Mode)
ON
T
ECHNICAL
CD always ON (Override)
Loads &F0 Generic template from read only memory (ROM)
Enables recognition (Smart mode)
Q R
UICK EFERENCE
161