OPERATION
3-1-38
[Define Repeat]
allows a repeat tone to be defined, by using the
[A]
to
[F]
keys and the key pad
and pressing [enter]. For example, if the repeat tone is defined as tone C, the sequence 11111
will be sent as 1C1C1 so that the receiver decoders will sense a change in frequency at the start
of each digit sent.
[Freq. Offset]
This facility alters the nominal tone frequency by a set percentage (up to ±10%)
for use in tolerance testing. To change the frequency offset value, select
[Freq. Offset]
and enter
the new value on the key pad. Terminate with the [%] key.
[Store Tones]
Up to 20 sequence set-ups can be stored. Use the key pad to enter the store
location number and press [enter].
[Recall Tones]
To recall a tone sequence, use the key pad to select the required store location
and press [enter].
[Start Delay]
The delay before the tone sequence starts and the gap between sequences can be
adjusted by pressing this soft key, entering the required delay time on the key pad and pressing
[ms].
[Mode Control]
Pressing this enables the user to assign the CALling tones to a selected type of
modulation, see Fig. 3-1-33. Modulation, on the selected channel, is turned off when the tones
are triggered and restored after the tones have been sent. Modulation on other channels is not
affected by the CALling tones and this allows sequential signaling tones to be combined with
sub-audible tones.
[NO Mod.]
This option effectively inhibits sequential tones. The tone
sequence can be sent between 1 and 9 times, set by
[No. of Repeats]
, every time the
[Send
Tones]
key is pressed. Setting the number of repeats to 10 allows the tones to be sent continually
under control of the
[Send Tones]/[Stop Tones]
key at the main menu.
Fig. 3-1-32 Sequential CALling tones utility menu (DTMF mode)
DTMF signaling capability is also provided with the NAV-750C. If this standard is selected then
the main menu accessed after pressing
the [CALling Tones]
soft key at
Utilities Selection Menu 1
will be as shown in Fig. 3-1-32. The functions of the soft keys are as follows:
[Tone Sequence]
Pressing this key allows a tone sequence to be set up using the digits 0-9 on the
numerical key pad and the soft keys
[A]
,
[B]
,
[C]
,
[D]
,
[*]
and
[#].
The sequence entry is
terminated by pressing [enter].
Tone
Sequence
Tone
Duration
Tone
Gap
Start
Delay
LOCAL
Mode
Control
Select
Standard
Store
Tones
Send
Tones
Recall
Tones
Sequential Calling Tones Utilty
Current Standard: DTMF
Mode: TOTAL FM - SINGLE SHOT
C1890
Tone Seq.:
Tone Duration
Tone Gap
Start delay
################
4-by-4 CCITT Touch-Tone Standard
:
:
:
70 ms
70 ms
200 ms
