The line signal reception test menu is selected by pressing the 9 button from the faculty test menu. This test checks the operation of the NCU signal sensor and
frequency counter. In Menu 1 the CI status can be detected and in Menu 3 the frequency can be detectet.
Test Menu 1
Test Menu 1 is selected by pressing the 1 button from the Line Detect menu. When CI is detected from the modular jack, the display changes from OFF
to ON and the received frequency is displayed. The on-hook/off-hook state of the handset and the external telephone is also displayed.
Test Menu 2
This item is not used.
Test Menu 3
Test Menu 3 is selected by pressing the 3 button from the Line Detect menu. When CNG is detected from the modular jack, the display changes from OFF