ZETRON Model 25, Руководство по эксплуатации продукта

Страница: 30 / 147

Operation
22 025-9567E
THE CALLING SEQUENCE
The calling sequence involves the keying of the audio, PTT, and control relays as well as the
sampling of the channel busy inputs and the generation of tones. There are several
programmable parameters that are helpful in tailoring the calling sequence to particular
applications. The “RELAY TIMING DIAGRAM” on page 28 also shows the relay keying
sequences.
The Control Relays
Aside from the PTT and audio relays, there are eight control relays that are generally used to
select the channel on which to send. Typically during a calling sequence one of the eight
control relays would be used to select a single channel. If the connected console allows, the
control relays may be used to key two or more channels for a “simul-cast” or “simul-select”.
The control relays used during a call sequence are determined by the key pressed to begin the
sequence. If one of the four
SEND
keys are used to start a calling sequence, then the
channel(s) used during the sequence are determined by the
SEND
key pressed. The
channel(s) used by a
SEND
key is specified by programming.
When sending calls using the Instant Call keys (or using the RETURN character if in remote
control) the control relays used are determined by the block or custom call number of the call
being sent at the moment. When an Instant Call key is used, each call of a call stack may be
sent on a different channel. This allows a single key to dispatch all personnel needed for a
particular event even though they may be listening to different channels. The channel(s) used
by each block or custom call is specified by programming.
Channel Busy Monitoring
There are four channel busy inputs, one associated with each
SEND
key. The LEDs adjacent
to the
SEND
keys show the busy state of the busy input for that key. Each key may be
programmed to either ignore or monitor its channel busy input. If the busy input for a key is
ignored then, sending via that key will proceed regardless of the state of its busy input.
If the busy input of a key is monitored then, sending via that key will be inhibited while the
input indicates busy. If an input is at the busy state and the associated
SEND
key is pressed
then the encoder will start a 30-second time-out during which the encoder will beep and blink
the word “
bUSY
”. If prior to the timeout, the input becomes clear or the
SEND
key is again
pressed, then sending will proceed immediately. If the time-out expires then the encoder will
give up the attempt to send the keyboard stack. The PTT or audio relays will never close
unless a call is sent.
When the Instant Call keys are used to send a call or stack of calls, the channel busy inputs
used depend on the control relays programmed against the calls to be sent. The inputs used
are the inputs of the
SEND
keys whose control relays in any way match the control relays
that are used by the call being sent. The following example may be helpful.