Sharp FO-90 Operation Manual page 82

Changing the number of rings
If desired, you can change the number of rings on which the fax
machine answers incoming calls in FAX and FAX/TEL modes. Any
number from 2 to 5 can be selected.
1
Press these keys:
The display will show:
NUMBER OF RINGS
ENTER (2-5) (2)
2
Enter the desired number of rings
(any number from 2 to 5).
The display will show:
TEL/FAX REMOTE #
3
Press the STOP key to return to the
date and time display.
Note: If you are using duplex ring, the machine will answer incoming
calls after two rings regardless of the above setting.
Using FAX Mode
FUNCTION
4
3
Example: 3 rings
STOP
81