Chapter 8 - Special Functions
8-7
If more than one type of Distinctive Ring is turned on, RING n will be reported
for an incoming ring signal where n is the ring type number.
Note: Countries other than the U.S. may have different specifications
for different ring types. The manufacturer may append other
sets of ring type specifications to suit each country's needs.
Extended Distinctive Ring (EDR)Extended Distinctive Ring (EDR) is a special feature designed for single
telephone line home use to receive fax or data calls without interfering with
regular voice calls. Most users, when they install a fax/modem at home, won’t
subscribe to an extra telephone line for occasional fax or data calls; however,
fax/data calls do come in from time to time.
If a user lets the fax/data software application answer, voice calls will be missed.
On the other hand, if a human being or an answering machine answers, fax or data
calls may either be missed or the person who answers the call has to go through
some procedures to get this call connected to the proper application. Either way
is not desirable.
Once enabled with the proper settings, EDR can:
1. Detect the data/fax CNG tone without physically answering the call. After a
CNG tone is detected, the modem will report RING or RING n to the
application software. The software can cause the modem to answer the call.
2. Detect several DTMF tones without physically answering the call. The
DTMF tones, once detected by the modem, will be reported as RING or
RING n to the software application.
With these two functions, the Omni 288S can be installed with an answering
machine or voice telephone set at home. In most cases, the modem should not be
set to answer regular rings, nor to report them. Thus, the software will not instruct
the modem to answer the call when phone rings. When a call comes in, the
answering machine will answer the phone and play a voice message. At this
moment, the modem, having detected the ring signal is gone, will start to listen to
the line for CNG tone or DTMF tones.
If the remote caller is an unattended fax machine, it will send a CNG tone for a
period of time. The modem will detect the CNG tone and report RING to the
software immediately. The software application can then issue commands to
answer the call and receive the fax. If the remote caller is using a fax phone which
does not send out a CNG tone and is waiting for a fax answer tone in order to
press the START button, the caller can press a designated DTMF tone, which
will activate the modem to report and subsequently be ordered to answer the fax
call.