Operating instructions

LOCAL OPERATION
3-83
When the DTMF TONES functions are set, return to the Rx TEST mode and enable the RF
generator. Return to the DTMF RF ENCODER function. Press the [Send Mode] key to display
the Send Mode menu. The options available are:-
[Cont Tones] Generates the tone sequence repeatedly until the orange [ON/OFF] function
key is pressed.
[Tone Burst] Generates one sequence of the tones then stops.
[Step Tones] The first press causes the first tone of the sequence to be generated for the
duration specified. When the [Step Tones] key is pressed again, the next tone in the
sequence will be generated for the duration specified.
[Single Tone] After pressing this key, pressing any data entry key will cause the
corresponding tone to be generated for the duration specified.
Using the appropriate keys to send the selected tones to the receiver, tests can be made to the
DTMF decoder.
Dx test DTMF tones function
When in Dx test mode the DTMF tones function can be accessed by pressing the [Tones] key.
The user can select encode or decode. The encode function will produce tones for mobile receiver
testing and decode will interpret tones produced by a mobile transmitter. The encoder and decoder
cannot operate simultaneously.
AF test DTMF tones function
The use of the DTMF tones function within the AF test mode allows the Service Monitor to
produce DTMF tones for direct injection into the DTMF decode circuits of mobiles or other
equipment.
The decoder will analyze DTMF tones produced within mobiles and other equipment.
The DTMF tones are obtained from the AF output connector on the front panel. The output levels
and impedances are as for the AF generator output.
The input to the DTMF decoder within the Service Monitor is through the AF input connector.
The decoder will respond to signal levels above approximately 150 mV rms.
Tones ON/OFF control
When the RF DTMF ENCODER screen or the AF DTMF ENCODER screen is displayed, the tone is
turned
ON or OFF by the orange [ON/OFF] function key.
If the DTMF tone is
ON and the Tx TEST, Rx TEST, Dx TEST or AF TEST mode selected, the
DTMF tone will continue to be generated.
If the tones out routing has been set to give RF tones, these are provided by modulation generators
1 and 2. The legend
--Tones-- will be displayed against both MOD1 FREQ and MOD2 FREQ on
the
RECEIVER TEST or DUPLEX screens. If MOD1 or MOD2 is selected, the DTMF tones can be
controlled by repeated presses of the orange [ON/OFF] function key. If
MOD1 FREQ or MOD2
FREQ is selected, the DTMF tones are still controlled by the [ON/OFF] key, but if a frequency is
entered using the data keys or if the variable control is adjusted, the DTMF tones will cease. They
can then be re-started only when the
RF DTMF ENCODER screen or the AF DTMF ENCODER
screen is displayed.
If the tones out routing has been set to give AF tones, this is provided by audio generators 1 and 2.
The legend
--Tones-- will be displayed against both AF1 FREQ and AF2 FREQ on the
TRANSMITTER TEST, DUPLEX or AF TEST screens. If AF1 or AF2 is selected, the DTMF tones
can be controlled by repeated presses of the orange [ON/OFF] function key. If
AF1 FREQ or AF2
FREQ
is selected, the DTMF tones are still controlled by the [ON/OFF] key, but if a frequency is
entered using the data keys or if the variable control is adjusted, the DTMF tones will cease. They
can then be re-started only when the
RF DTMF ENCODER screen or the AF DTMF ENCODER
screen is displayed.