Brother MFC-7050C, Owner'S Manual

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I N T R O D U C T I O N
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oduction
When your MFC answers in FAX/TEL mode, the MFC 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 fax 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 40 seconds after the number is dialed.
Therefore, it’s important for the receiving machine to answer the
call in as few rings as possible.
When you have an external telephone answering device (TAD) on
your MFC line, your TAD will determine the number of rings
before the call is answered. Pay special attention to the directions
for connecting a TAD to your MFC in the MFC Setup and
Connections chapter.
ECM (Error Correction Mode)
The Error Correction Mode (ECM) is a way for the MFC 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 MFC for this feature
to work.