Cloud Electronics PM12 - Manual (Page 29)

PM4/8/12/16 Installation and User Guide v2.2 29
Using the analogue interface with multiple PMs
The “last” mixer in the chain – that connected to the host mixer – may be connected
to the host via the analogue interface instead of the Digital Paging Interface, if the
host mixer is not equipped with the digital interface. Connect the PM in the same
way as if it was the only PM in the system, using separate audio and control cables.
See page 18 for full details.
Communication between PMs will be via the digital interface, and between the last
PM (effectively the whole network) and the host will be via the analogue interface.
Consideration needs to be given to any zone offsets applied to the various PMs on
the network. For example, in a 12-zone system with three PM4s configured to page
Zones 1 to 4, 5 to 8 and 9 to 12 respectively, analogue port terminals Z1 to Z12
inclusive will need to be wired to the host mixers for correct operation.
Priorities
A potential problem exists in paging systems employing multiple paging microphones
in the form of announcement “collisions”. A collision will occur if an announcement
is attempted from one paging microphone while another is already in progress. As
any one microphone will probably only be in earshot of one zone’s loudspeakers,
it is possible for a microphone to be paging a zone and operators at other paging
(with Digital Paging Interface)
Mixer
MIC INPUT PAGING ACCESS
Mixer
+12V Z1 Z2 Z3 Z4 Z5 Z6 Z7 Z8 0V
LF HF GAIN (dB)
50
1 2 3
10
+ - - +
(with Analogue Paging Interface)
IN OUT OUT
Termination OFF
CAT-5 CAT-5
CAT-5 CAT-5 CAT-5
(INCLUDING DC POWER FROM MIXER)
(INCLUDING DC POWER FROM MIXER)
Termination
OFF
Termination ON
IN OUT
Termination
ON
IN OUT
AUDIO OUT
ZONE ACCESS CONTROL
Termination
OFF
IN OUT
Termination
ON
PSU PSU
PSU PSU
CDPM
GAIN (dB)
IN THRU
-10 +10
Termination ON T