ENC-3300-DTMF
CDWAIT – Carrier Detect wait time in seconds
Purpose:
Adjusts the amount of time the ENC-3300 will wait for the channel to clear before attempting to
transmit. If the Carrier Detect is still busy when the CDWAIT time expires, the attempt is aborted and
no signal is sent.
Minimum value: 0 Zero disables Carrier Detect. Channel activity will not be checked before transmit.
Maximum value 65535. When set to 65535, the ENC-3300 will not time out. A power reset or pressing
the ESC key may be necessary to abort the attempt if the channel does not become available.
Overview:
The carrier detect line input of the ENC-3300 can be connected to the carrier detect output of a two-
way radio to monitor the radio channel and avoid transmitting if the channel is already in use.
The ENC-3300 checks the carrier detect just before it engages relay 8 to keyup the radio. If the
channel is busy it will wait until the channel is available before continuing with it's transmission. If the
channel remains busy past the time set by CDWAIT, the ENC-3300 will abort the attempt and the
signal will not be sent.
Hardware connection:
The Carrier Detect (
/CD
) input on the ENC-3300 is an active low. This means the
/CD
wait logic
engages when the
/CD
input is taken low in respect to the ENC's ground.
Most two-way radios supply a logic low output when the channel is busy which usually matches the
ENC's input quite well. It is important however to remember that the ENC-3300 and your radio must
share a common power ground for CD to operate. If a common ground can not be attained, or if your
radio raises it's carrier detect when there is a busy channel, then it may be necessary for the installer
to add an isolation relay, opto-coupler or other techniques to complete the interface.
See PRIORITY on page 40 for information on overriding carrier detect on a per-button level.
SIDETONE
The side tone from the internal speaker can be enabled or disabled when sending DTMF digits.
SYS,SIDETONE=0;
// zero disables side tone
SYS,SIDETONE=1;
// one enables dtmf side tone
This setting only affects the side tone as the encoder is generating the DTMF digits. Even with
“SIDETONE” set to zero, the speaker will still beep for button presses, countdown timers, errors and
other prompts.
Genave/NRC,Inc. 9000-0000-086 rev 4
Pg. 36