Oce 3121 Technical & Service Manual page 906

Line Test (LINE DETECT)
I
Press 'LINE TEST' and press ' OK ' to start the line test, and to invoke the
corresponding screen.
This mode tests the sensors around the NCU and the frequency counter.
(1) LINE DETECT 1
Press 'LINE DETECT 1. Press ' OK ' to invoke the corresponding screen
This function will check CI, Fc and hook state (ON/OFF) from the line.
For CI, the appropriate frequency (0 if CI is off; the current CI frequency if
ON).
94 TSM Océ 3121 SDS Description