c) CNG and DTMF signal reception tests
The CNG and DTMF signal reception test is selected by pressing the 6 button from the
MODEM NCU test menu. In these tests, you can check whether the CNG signals and
DTMF signals received from the modular jack are detected by the modem.
The CNG is not
The CNG is
Figure 3-29 CNG and DTMF Signal Reception Tests
4-6: TONE RX
0 O F F N O E N E R G Y
O O N
Chapter 3: Maintenance & Service
The received DTMF "9"
2nd received DTMF "2"