Operating instructions

LOCAL OPERATION
3-76 46882-311D
[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 routeing 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 or is selected, the
DTMF tones can be controlled by repeated presses of the orange [ON/OFF] function key. If
or 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 routeing 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 or is selected, the DTMF tones
can be controlled by repeated presses of the orange [ON/OFF] function key. If
or
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.
POCSAG
Overview
The POCSAG system is an international standard for radio pager operation. The system operates
by broadcasting digital messages on a common frequency, only alerting the addressed radio pager
when the transmitted address matches that of the pager. The signal transmitted consists of two
main elements, the address and the message.