Motorola MSF 5000 Instruction Manual page 248

Appendix C MUXbus Descriptions
MSF
5000
Instruction Manual
MUXbus Overview
DAT
PTT
SCAN
T
ALM DS
S
ALM DS
C-2
The MUXbus is
a time multiplexed address and data bus
with
16
addresses, each
containing four data bits. The SSCB serves
as the
MUXbus
master and
drives
the
address and Data Strobe
(DS)
lines.
The
address lines
are
periodically
incremented, and the
DS
is used
to synchronize the read/write cycles.
Since the
MUXbus is available to all control modules in
the
main and expansion
trays, all modules may read and write data
to the
MUXbus. Using
the MUXbus,
wildcards
and special application boards
in
the expansion tray may easily be used
to create special functions that
are
not
a
standard offering
with
the station.
The following descriptions define each of the 64 MUXbus
bits.
Each definition
includes the mnemonic (abbreviation), a spelled-out description, and the
associated
row/column address on the
MUXbus.
Data
Push-To-Talk (A0/D3)
Indicates
if
a
Data
PTT
request is active. When active,
the request
is arbitrated
against all other active PTT
requests.
The
PTT
priorities may
be changed
via
the
field Programmer or
with
option C672.
Scan Enable
(A0/D2)
In stations equipped with
scan option C42, this bit activates receiver scanning.
When active,
the station scrolls through programmed channels,
stopping when
receiver activity is detected.
Total Alarm Disable (A0/D1)
Unconditionally
mutes
all alarm
tones generated
in
response to
active reverse
wildcards bits on addresses
12
and
13.
See also
S
ALM
DS.
Selective
Alarm Disable (A0/D0)
Mutes repetitive alarm
tones generated
in
response to
active reverse wildcard bits
on addresses
12
and
13.
For example, when
a
reverse
wildcard bit is active,
a
corresponding number of alarm
tones are generated
every
ten seconds.
When
S
ALM
DS
is active, the alarm tones are
only
sent once; they are not repeated
every
ten seconds.
68P81092E11
3/19/94
es