4-60LASER CLASS 1060P Chapter 4: Maintenance & Service5.1.5 Modem and NCU testsThese tests test modem and NCU transmission and reception. The modem tests check whether signals aresent correctly from the modem by comparing the sound of the signals from the speaker with the sounds froma normal modem. Also, on the display indicates whether or not the modem correctly detected received tonesignals and DTMF signals.End this test by pressing the STOP button.Modem test type OverviewFrequency test The modem sends tone signals from the modular jack and thespeaker.G3 signal transmission test The modem sends G3 signals from the modular jack and thespeaker.CNG signal reception tests The modem detects specific frequencies and DTMF signalsreceived from the modular jack.a) Frequency testThe frequency test menu is selected by pressing numeric button 2 from the MODEM NCU test menu.Signals of the frequencies below are sent from the modem using the modular jack and the speaker. Thefrequency can be changed with the numeric buttons.Numeric button Frequency1 462 Hz2 1100 Hz3 1300 Hz4 1500 Hz5 1650 Hz6 1850 Hz7 2100 HzNOTEThe pseudo-ringback tone transmission pattern and frequency and the output levels foreach frequency follow the service data transmission level settings.