Brother IntelliFax-2600 Service Manual page 97

Selectors 5 and 6: Busy tone detection in automatic sending mode
These selectors determine whether or not the equipment automatically disconnects a line upon
detection of a busy tone in automatic sending mode.
Setting selector 6 to "0" ignores a busy tone so that the equipment does not disconnect the line.
Setting selectors 5 and 6 to "0" and "1," respectively, makes the equipment detect a busy tone only
after dialing and disconnect the line.
Setting both of selectors 5 and 6 to "1" makes the equipment detect a busy tone before and after
dialing and then disconnect the line. Note that no busy tone before dialing will be detected in those
countries not supporting the dial tone detection (e.g., U.S.A.).
Selector 7: Busy tone detection in automatic receiving mode
This selector determines whether or not the equipment automatically disconnects a line upon
detection of a busy tone in automatic receiving mode.
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