iPAM400 – Product Manual
U-0629-0171.doc – Issue: 04 complete, approved
Page 128 of 138
Figure 27 Control signal operation – PA system lightly used by lower priority audio sources
CONTROL SIGNAL
OPERATION
SYSTEM SET UP FOR THE LLPA
TO HAVE NO KNOWLEDGE OF
LOWER PRIORITY
BROADCASTS - BUT AS A
RESULT TO BE HIGHLY
CONFIDENT OF MAKING A
BROADCAST WHEN ONE IS
REQUESTED
AUDIO (FROM LLPA)
ACCESS GRANTED (FROM PA)
ZONE BUSY (FROM PA)
UNSUCCESSFUL BROADCAST
ACCESS REQUEST / SELECT (FROM LLPA)
ACCESS REQUEST / SELECT (FROM LLPA)
AUDIO (FROM LLPA)
ACCESS GRANTED (FROM PA)
ZONE BUSY (FROM PA)
SUCCESSFUL BROADCAST
LLPA BROADCAST TERMINATED BY
PA SYSTEM DUE TO HIGHER
PRIORITY OVERRIDE
THE ZONE BUSY LINE SHOWS
ACTIVITY INTO THE ZONE BY HIGHER
PRIORITY SOURCES ONLY.
THEREFORE THE LLPA HAS NO
KNOWLEDGE OF LOWER PRIORITY
BROADCASTS, AND MAY INTERRUPT
THEM.
HOWEVER THE LLPA WILL NOT
COMMENCE A BROADCAST UNLESS
THE ZONE BUSY LINE IS INACTIVE.
THEREFORE THE LLPA HAS A HIGH
PROBABILITY OF GAINING ACCESS
FOR ANY ATTEMPTED BROADCAST.
Figure 28 Control signal operation – PA system heavily used by lower priority audio sources
CONTROL
SIGNAL
OPERATION
SYSTEM SET UP FOR THE
LLPA TO ATTEMPT TO AVOID
INTERRUPTING LOWER
PRIORITY BROADCASTS
THE ZONE BUSY LINE SHOWS
ACTIVITY INTO THE ZONE BY ANY
SOURCE, INCLUDING SOURCES OF
LOWER PRIORITY THAN THE LLPA
SYSTEM.
THEREFORE THE ZONE BUSY LINE
MAY BE USED TO MAKE A
DECISION TO NOT INTERRUPT A
LOWER PRIORITY BROADCAST BY
NOT ATTEMPTING TO BROADCAST
WHEN IT IS ACTIVE.
HOWEVER THE ZONE BUSY LINE
DOES NOT DIFFERENTIATE
BETWEEN HIGHER AND LOWER
PRIORITY BROADCASTS, SO THE
LLPA DOES NOT KNOW IF IT WILL
GAIN ACCESS IF IT DOES TRY TO
BROADCAST WHEN THE ZONE
BUSY LINE IS ACTIVE
ACCESS REQUEST / SELECT (FROM LLPA)
AUDIO (FROM LLPA)
ACCESS GRANTED (FROM PA)
ZONE BUSY - ANY SOURCE (FROM PA)
SUCCESSFUL BROADCAST
AUDIO (FROM LLPA)
ACCESS GRANTED (FROM PA)
ZONE BUSY - ANY SOURCE (FROM PA)
UNSUCCESSFUL BROADCAST - OVERRIDDEN
LLPA BROADCAST TERMINATED BY PA SYSTEM
DUE TO HIGHER PRIORITY OVERRIDE
ACCESS REQUEST / SELECT (FROM LLPA)
ACCESS REQUEST / SELECT (FROM LLPA)
AUDIO (FROM LLPA)
ACCESS GRANTED (FROM PA)
ZONE BUSY - ANY SOURCE (FROM PA)
UNSUCCESSFUL BROADCAST - NO ACCESS GRANTED
LLPA ACCESS ATTEMPT ABANDONED
AFTER LACK OF ACCESS GRANTED REPLY
LLPA ACCESS ATTEMPT MADE
To Next Page
Loading...
