Canon GP160DF Service Manual page 571

d) DTMF signal output test
When 5 on the numeric key pad in the MODEM NCU TEST menu is pressed, the
DTMF signal transmission test is selected. This test uses the telephone line connection
terminal and the speaker to output the DTMF signals from the modem shown below.
The DTMF signal corresponds to the key pressed on the numeric key pad.
Remarks:
The output level of each signal conforms to the service mode settings.
e) Tonal, DTMF signal reception test
When 6 on the numeric key pad in the MODEM NCU TEST menu is pressed, the
tonal signal and DTMF signal reception 0 test is selected. This test checks whether the
tonal signal and DTMF signal received from the telephone line connection terminal was
detected.
Tonal signal reception test
4-6 : TONE Rx
0 0 0
Tonal signal reception test
4-6 : TONE Rx
The DTMF signals received on the display's second line are displayed in order from the right.
000
Changes from 0 to 1 when a 462 ± 25Hz signal is detected
Changes from 0 to 1 when a 1100 ± 30Hz signal is detected
Changes from 0 to 1 when a 2100 ± 25Hz signal is detected
000
1 2 3 4 5 6 7 8 9 0
Figure 4-21
CHAPTER 4 SERVICE MODE
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