ENC-3300-DTMF
Relays
Two “dry contact” Form-C relays on the board are used to interface with the radio. They are switching
relays which do not deliver any voltage from the encoder.
PTT – Relay 8
Relay 8 is normally attached to the push-to-talk line of the two-way radio.
The relay engages prior to a DTMF code string being transmitted and remains engaged until the
DTMF code string has finished. The “Tx” indicator is lit whenever this output is engaged.
It can also be controlled during a transmission by using commands
[R8=0]
and
[R8=1]
in the DTMF
code string to turn the relay off and on respectively.
Relay 8 has all three of its form-C contacts available on output connector J3. Normally Open, Normally
Closed and Common pins are all available.
Aux – Relay 7
Relay 7 provides secondary functions that can be used as necessary to control operations such as
microphone on/off, transmitter steering or other external devices. It does not automatically engage
during a transmit event but is instead controlled by commands in the DTMF code string.
Commands
[R7=0]
and
[R7=1]
in the DTMF code string turn the relay off and on respectively.
Relay 7 has two of its form-C outputs available on output connector J3. Normally Open and Common
pins are available.
Audio
The ENC-3300 uses an internal 600 ohm matching transformer to provide superior audio response,
isolation and minimum signal loading between the radio and the encoder.
The audio output level is adjusted with Pot 1 which is also labeled “
Tx Audio Level
”. Turning the
control clock-wise results in higher audio output level.
Connector J3 has the two isolated audio outputs. They are labeled “
Audio 1
” and “
Audio 2
”
and have no ground connection to the encoder.
10 second test switch
The 10 Sec Test switch engages relay 8, delivers a test tone for ten seconds then disengages relay 8.
The switch is used to adjust transmitter deviation levels during installation and system maintenance.
Genave/NRC,Inc. 9000-0000-086 rev 4
Pg. 26
