Siemens 1800C - Manual (Page 23)

I N T R O D U C T I O N 1 - 6
The receiving fax responds with fax receiving tones—loud, chirping sounds.
A receiving fax chirps for about 40 seconds over the phone line, and the LCD
shows
RECEIVING . If your fax machine is set to the FAX mode, it will answer
every call automatically with fax receiving tones. Even if the other party hangs
up, your fax machine continues to send the “chirps” for about 40 seconds, and
the LCD continues to display
RECEIVING . To cancel the receiving mode,
press Stop/Exit.
When your fax machine answers in FAX/TEL mode, it listens for CNG tones
and then responds with receiving tones.
The fax “handshake” is the time in which the sending machine’s CNG tones and
the receiving machines “chirps” overlap. This must be for at least 2 to 4 seconds,
so the machines can understand how each is sending and receiving the fax. The
handshake cannot begin until the call is answered, and the CNG tones only last
for about 60 seconds after the number is dialed. Therefore, it’s 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 the
integrity of a fax transmission while it is in progress. ECM transmissions are
possible only between machines that both have the ECM feature. If they do, you
may send and receive fax messages that are continuously checked for their
integrity.
Sufficient memory must be available in your fax machine for this feature to
work.
Note
When you have an external telephone answering device (TAD) on your fax
line, your TAD will determine the number of rings before the call is answered.
Pay special attention to the directions chapter for connecting a TAD to your fax
machine in Chapter 2,
Assembly and Connections .