User's Manual

18
&Cn Mode Indicator - The Mode Indicate Pin (3) reflects whether the module is In
Data Mode or Command Mode. A Low output indicates the module is in
connected (Data Mode). If this output is High, the module is ready to receive
commands (Command Mode). The MI signal can be forced with the AT&Cn
command.
&C0 Mode Indicate signal is forced high.
&C1 Mode Indicate signal will indicate whether the module is in On Line Data
Mode or Off Line Command Mode (default).
D Initiate Wireless RF Link - This command instructs the module to initiate a
wireless RF link with a remote WHM900. The remote module must enter an
“ ATA” command. The module will wait the amount of time defined in module
resister ATS7 to establish a RF link with the remote module. If the link is
unsuccessful, the module will return to the off line command mode. The ATD
command is also used for auto pole detection for all available frequencies and
IDs. See the ATMn or AT%U commands for more information on using the auto
pole search option.
&Dn DTR (Data Terminal Ready) Option. The DTR signal must be provided either by
command or an incoming signal from the host equipment to enable data
communications between two WHM900 modules. If either the ATA or the ATD
commands are issued without a DTR signal available, the “ NO DTR “ result code
will be displayed.
&D0 Ignores DTR (DTR signal is forced on Pin 6) (default).
&D1 An On-to-Off transition will cause the mode to enter the On Line
Command Mode. It has the same effect as entering the Escape code (+++).
This allows you to change certain commands without losing the data link
and then go back into the Data Mode with the ATO<CR> command.
&D2 Host equipment controls the DTR signal. The module assumes command
state and disables data communication when detecting ON-to-OFF
transition of DTR. To establish a data communications, DTR must be On
and an ATA or ATD must be issued
&D3 Module responds to a DTR On-to-Off transition as though a reset
command (ATZ) had been received.