Motorola MSF 5000 Instruction Manual page 249

MSF
5000
Instruction Manual AppendixC MUXbus
Descriptions
RPT PTT
LIN
PTT
68P81092E11 3/19/94
MUXbus Overview
There
are
two modes of operation when using the Selective
Alarm
Disable
feature.
Mode
A
is to set this
bit
on the
MUXbus
and continue
driving
it active. In
this mode, the SSCB
will
generate alarm tones
only
once;
however, it
will
generate
the tones
whenever
the state of the reverse
wildcard bits
changes.
The
user
will
hear one
full
set
of alarm
tones
whenever
the
alarm status changes (unless the
change is to
all alarms cleared).
Mode
B
is to set the
MUXbus
bit for
at lease 20 msec,
and then stop
driving
it
active. The SSCB
then latches the
bit active, even though
the
original driver
has
released the bit.
When
the state of the reverse wildcard bits change,
the
SSCB
stops
holding
the
S
ALM
DS
bit active. This has the effect of stopping alarm
tone
generation completely until the alarm status changes, then normal alarm tone
generation is resumed; alarm tones
are
generated
every
ten seconds.
The SSCB
also stops holding this bit active when
the
T ALM
DS bit is activated.
Repeater Push-To-Talk (A1/D3)
Indicates that
a
Repeater
PTT
or
Trunking
PTT
is active.
If this
is the
highest
priority active PTT, then the audio gating
will
be set for in-cabinet
repeat.
If
the
repeater
PTT
time-out timer
(TOT)
times out, the
RPT PTT
bit
will
stay active
until
the request goes
away; however,
the active
PTT
type
will
change
to the next
active lowest priority,
if
any.
PTT
priorities
are set on a
per mode basis
by
the
Field Programmer
or
with
option C672.
If
repeater
knock down
(RPT KD)
goes active
while
RPT PTT
is active,
PL
reverse
burst or
DPL
turn off code
(RB/TOC) will
be
encoded
if
appropriate, and the
transmitter
will
de-key.
RPT PTT
is active
during
repeater
drop-out delay and is
inactive when RB/TOC is encoded.
The SSCB activates
RPT PTT if
qualified
repeater
audio
activity
exists on Receiver
1. Qualified
repeater
audio
activity
can be
set
for each mode
by
the
Field
Programmer
or
with
option C673. Qualified repeater audio
activity
is determined
by any
combination of
MUXbus
bits
RX PL
DS,
R1
PL
DT,
RPT USQ,
and
AUX
DET.
The
RPT PTT
bit is
a
STATUS-ONLY
bit.
This means that the bit is used for
indication purposes
only.
Activating
this bit via
the
DMP
or
wildcard module
will
not cause
the station to
key
or gate repeater audio.
Only
the
SSCB may
determine
that the repeater squelch qualifiers have been met and allow the station to repeat.
Line Push-To-Talk (A1/D2)
Keys
the transmitter,
modulating with
TX
Audio if
no higher
priority
PTT
is
active.
PTT
priorities
are set on
a
per mode basis
by
the
Field Programmer
or
with
option C672.
LIN PTT
is inactive when RB/TOC is encoded, unless the RB/TOC
is caused
by
the
Line
PTT
timing
out.
This bit
is usually written to the
MUXbus by
the
TTRC
module in response
to a
console request to
key
the station.
C-3