Specifications
LBI-39062
9
In a typical C3 Maestro console installation, the Audio
Tower is equipped with only one Audio PA Board (#1) and
this board is installed in the slot position adjacent to the
Audio Matrix Board. In this installation, a blank cover
plate is installed over the unused far right-hand slot
position. However, a 3- or 4-speaker console or console
connected to a Call Director requires a second Audio PA
Board (#2) installed in the Audio Tower's far right-hand
slot position. In this case, the blank cover plate is not
employed.
All Console Installations
All C3 Maestro console installations use Line A on the
first Audio PA Board (#1) to couple select audio from the
CIM and mic audio to the CIM. Also, one-half of Line B
(the input pair) is used to couple unselect audio from the
CIM. The other half of Line B (the output pair) is not used.
Line A and B are connected to CIM channels 1 and 2
respectively.
Speaker A output drives the select speaker and Speaker
B drives the first unselect speaker. Some installations may
not employ speakers and thus connection to the speaker
outputs are not required.
Multiple Unselect Speakers or
Call Director Patch Installation
In a multiple unselect speaker or Call Director patch
installation, Line A and B balanced lines at the second
Audio PA Board (#2) are considered Line C and D
respectively. These balanced lines couple to CIM channels
3 and 4 respectively. One-half of Line C (board #2 Line A)
carries the second (2) unselect audio from CIM channel 3;
the other half (the output pair) is not used. Line D (board
#2 Line B) couples Call Director patch audio to and from
the CIM or, if no Call Director patch is present, it may be
used to couple the third (3) unselect audio to the console
from CIM channel 4. Unselect audio speaker routing
configuration is accomplished using the console's "MODULE
FUNCTIONS" note card.
Audio Matrix Board
The primary purpose of the Audio Matrix Board in the
Audio Tower is to route or switch audio signals from an
input source(s) to the appropriate output destination(s).
This routing is accomplished via audio matrix circuitry on
the board as controlled by the PC and the Logic Board. The
PC and Logic Board control the Audio Matrix Board (and
all other circuitry in the Audio Tower) via the 37-conductor
interconnect cable.
For example, when a dispatcher keys the desk mic, the
PC commands the Audio Matrix Board to switch the desk
mic audio input (source) through the audio matrix to the
Line A output (destination). This audio is applied to
channel 1 of the console's CIM within the CEC/IMC.
Other Audio Matrix Board functions/circuits include:
• audio conditioning for the supervisor headset,
operator headset, desk mic and boom/gooseneck
mic inputs
• mic PTT interfacing to the PC
• mic sense (connected/not connected) interfacing to
the PC
• headset audio amplification for the supervisor and
operator headset earphone audio outputs
• pager audio input coupling and page
enable/disable input interfacing to the PC
• Call Director patch coupling audio and control
interfacing
• relay drive logic
Audio routing on the Audio Matrix Board is
accomplished via the audio matrix. This matrix consists of
eight (8) "cross-point switch" integrated circuits which
each have an 8 x 8 switch matrix. All console audio signals
are routed through the matrix ICs. Input signals are applied
to the "Y" side of the matrix and output signals are sent out
from the "X" side. Audio matrix and other circuitry on this
board is controlled by the Logic Board inside the PC and
the C3 Maestro application program running on the PC
From top to bottom, the connectors on the Audio
Matrix Board's front panel provide:
• supervisor headset mic and earphone connections
(DB-9 subminiature connector)
• operator headset mic and earphone connections
(DB-9 subminiature connector)
• desk mic connections (DB-9 subminiature
connector)
• boom or gooseneck mic connections (DB-9
subminiature connector)
• PC interfacing (DB-37 subminiature connector)
Several microphones may be concurrently connected to
the C3 Maestro console system via the Audio Matrix Board.
These include the mics in the supervisor and operator
headsets, a desk mic, and a boom or gooseneck mic. Mic
jack sense circuitry on the Audio Matrix Board and the
Logic Board within the PC determine which mic audio
signal will be used when the console is keyed. The console
may be keyed from either the Dispatch Keyboard, a push-