Service manual

Operating the System Remotely C-23
This default initialization string works on a wide variety of modems. If your modem
does not configure itself to these parameters, the initialization string will need to be
modified. See the topic in this section entitled Modifying Initialization and Answer
Strings.
Ring Detection
The RCM expects to be informed of an in-bound call by the modem signaling the
RCM with the string, “2<cr>” (RING).
Answer
When the RCM receives the ring message from the modem, it responds with the
answer string. The “X” command modifier used in the default answer string forces
the modem to report simple connect, rather than connect at xxxx. The RCM expects
a simple connect message, “1<cr>” (CONNECTED). If the modem responds with
anything else, the RCM forces a hang-up and initializes the modem.
The default answer string is formatted to request the modem to provide only basic
status. If your modem does not provide the basic response, the answer string, and/or
initialization string will need to be modified. See the topic in this section entitled
Modifying Initialization and Answer Strings.
After receiving the “connect” status, the modem waits for 6 seconds and then
prompts the user for a password.
Hangup
When the RCM is requested to hang up the modem, it forces the modem into
command mode and issues the hangup command to the modem. This is done by
pausing for a minimum of the guard time, sending the modem “+++”. When the
modem responds with “0<cr>” (OK), the hang-up command string is sent. The
modem should respond with “3<cr>” (NO CARRIER). After this interchange, the
modem is reinitialized in preparation for the next dial-in session.