Introduction 1 - 7
Fax tones and handshake
When someone is sending a fax, the fax machine sends fax calling
tones (CNG tones). These are quiet, intermittent beeps every
4-seconds. You’ll hear them after you dial and press Fax Start and
they will continue for about 60 seconds after dialing. During that
time, the sending machi ne must begin the “handshake” with th e
receiving machine.
Each time you use aut omatic procedures to send a fax, you ar e
sending CNG tones over the phone line. You’ll soon learn to listen
for these quiet beeps each time you answer a phone on your fax
line, so you will know if you are receiving a fax message.
The receiving fax resp onds with fax recei ving tones, which a re
loud, chirping sounds . A receiving fax c hirps for about 40 seconds
over the phone line, an d the LCD shows RECEIVE.
If the fax machine is set to the FAX ONLY mode, it will answer every
call automatically with fax receiving tones. If the other person
hangs up, the fax machine will continue to send the “chirps” for
about 40 seconds, and the LCD continues to show RECEIVE. To
cancel the receiving, press Stop/Exit.
The fax ‘handshake’ i s the time in which the sending machi ne’s
CNG tones and the receiv ing machines “ch irps” overlap. T his must
be for at least 2 to 4 seconds, so the fax machines can understand
how each is sending and receiving the fax. The handshake cannot
begin until the call is answe red, and the CNG tones on ly last for
about 60 seconds after the number is dialed. So it is important for
the receiving machine to answer the call in as few rings as
possible.
ECM (Error Correction Mode)
The Error Correction Mode (ECM) is a way for the fax machine to
check a fax transmission while it is in progress . ECM transmiss ions
are only possible between machines that both have this feature. If
they do, you may send and receive fax messages that are
continuously being che cked by the fax ma chine.
The fax machine must have enou gh memory for this feature to
work.
When you have an exter nal Telephone Answ ering Device
(TAD) on your fax line, your TAD will decide the number of
rings before the call is answered.
Pay special attention to the directions for connecting a TAD in
this chapter. (See Connecting an ex ternal telephone
answering device (TAD) on page 1-8.)