Brother MFC-4300 User Manual

      I N T R O D U C T I O N

If you’re a first-time fax machine user, fax operation might seem a little 
mysterious. Soon, you’ll recognize the unusual fax tones on your phone line, 
and be able to send and receive faxes easily. 

When someone is sending a fax, the MFC sends fax calling tones, (CNG tones) 
— soft, intermittent beeps at 4-second intervals. You’ll hear them when you dial 
and press 

, and they continue for about 40 seconds after dialing. During 

that time, the sending machine must begin the “handshake” with the receiving 
machine. Each time you use automatic procedures to send a fax, you are sending 
CNG tones over the phone line. You’ll soon learn to listen for these soft beeps 
each time you answer a phone on your fax line, so you can know if you are 
receiving a fax message.

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 screen 
displays RECEIVE. If your MFC is set to the FAX mode, it will answer every 
call automatically with fax receiving tones. Even if the other party hangs up, 
your MFC continues to send the “chirps” for about 40 seconds, and the screen 
continues to display RECEIVE. To cancel the receiving mode, press 

.

When your MFC 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 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.

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 MFC for this feature to work.

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 in the Installation chapter for connecting 
a TAD to your MFC.