6K V1.02 03-16-91
37
have finished entering a command. The "*" will always work as a terminator. You can also allow a
carrier drop to work as a terminator if you wish; the carrier drop method can be turned on and off,
but the "*" method can't be turned off, and will terminate any command.
Why do we have the two methods? It's easier to terminate a command by simply releasing the PTT
(push-to-talk) button on your microphone, and you have saved one keystroke (the "*"). However,
there could be a weak carrier on the repeater's input frequency some day when you enter a
command. If the carrier continues to hold up the repeater after you've released the PTT button,
your command won't be executed. Entering the "*" at the end of the command will guarantee that
the command is properly terminated.
A second reason for using the "*" terminator is that you may enter a series of commands, one after
the other, without releasing the PTT button. (You do not have to wait for the acknowledgement
message before entering the next command). You must, of course, use the "*" terminator when
entering commands from a Touch-Tone (R) telephone, since there is no carrier drop for the
controller to detect.
The pound (#) digit serves as a "clear" or "abort" key. It indicates to the controller that you have
made an error, and you wish to clear the command buffer. (The command buffer is a holding area
for the partially-entered command). The "#" key only works if the command is still in the buffer, and
has not been executed. When you enter the terminator, the command is immediately executed
and it is too late to clear the buffer. You may start entering the next command immediately after
pressing the "#" key. There is no acknowledgement message sent by the controller when a
command is cleared. Any digits following the "#" digit will be considered a new command.
5.
DTMF INTERDIGIT TIMER
The controller uses a DTMF Interdigit Timer for the purpose of clearing the command buffer if a
command is not completely entered. For example, if a user accidentally presses a digit, or if a digit
is "falsed" into the buffer, or if a user drives out of range or his signal flutters while entering a
command, then the command buffer will have only a piece of a command. If the controller had no
time limit between digits, then that piece of a command would stay in the buffer. The controller
would confuse it with the next command it receives.
The Interdigit Timer works as follows: When you release any DTMF key, the timer is started. If you
do not enter another DTMF digit within the time limit, the controller will clear the command buffer.
The Interdigit Timer initially defaults to 5.0 seconds, but it can be reprogrammed with a different
value if desired.
6.
DTMF MUTE DELAY
The controller has a DTMF Mute feature that prevents your DTMF commands from being repeated.
This feature can be turned on and off.
Unless your controller has been fitted with the optional Audio Delay Module, there will be a short
burst (40 ms to 50 ms) of DTMF that is repeated at the beginning of a digit. This short burst occurs
because the controller requires some time to detect the DTMF digit and shut off the audio gate.
To reduce the number of bursts, the controller will continue to mute the audio for a while after you
have released the DTMF key. Thus, if you enter a string of digits rapidly, there will be only a single
