Specifications

LBI-39062
10
to-talk (PTT) button at one of the connected mics or a
footswitch.
A pager audio input is provided at the I/O Board.
When enabled, paging audio overrides all other mic audio
inputs.
I/O Board
The I/O Board used in the Audio Tower interconnects
signals between the Audio Tower’s Backplane Board and
the terminal blocks and connectors located on its front
panel. In a typical C3 Maestro console installation, no or
only a few devices are interconnected the I/O Board. It
contains no active electronic components.
The I/O Board is inserted into the Audio Tower's far
left-hand slot. From top to bottom, connectors on the
board's panel provide:
• select and unselect recorder audio outputs
(terminal block connector)
• pager audio and pager enable ("PTT") inputs
(terminal block connector)
• Call Director patch audio/control inputs and
outputs (DB-9 subminiature connector)
• boom/gooseneck and monitor switch inputs
(terminal block connector)
• footswitch 1 inputs for desk mic PTT and monitor
switch functions (DB-9 subminiature connector)
• footswitch 2 inputs for boom/gooseneck mic PTT
and monitor switch functions (DB-9 subminiature
connector)
• digital inputs (terminal block connector; these
inputs not supported)
• relay Form-A contact outputs (terminal block
connector)
VOLUME CONTROLLER BOX
The Volume Controller Box contains volume controls
for the speakers. Normally, there are two (2) volume
controls, one for the select speaker and one for the unselect
speaker. This box is not required if the console is not
equipped with speakers.
Audio signals are not routed through the Volume
Controller Box. Instead, each volume control's
potentiometer sets a dc voltage which in turn controls the
gain of the respective speaker's audio amplifications
circuitry on the Audio PA Board.
CALL DIRECTOR PATCH
The C3 Maestro console system can be connected to
Call Director (CD) telephone patch equipment. This feature
allows the C3 Maestro to "patch" a telephone line to a
specific unit, talk group, conventional channel or radio
patch in the CEC/IMC network. See Figure 3.
The term patch or patched, derived from phone patch,
is used to convey the CD is connected to the CEC/IMC. A
Call Director patch should not be confused with a radio
patch in which a collection of radio talk groups are
interconnected for common communications as one group.
Call Director patch operates independently of normal
console-to-radio dispatch communications. Using the CD
interface, the dispatcher is only required to connect the CD
with the target entity (unit, group, etc.). After this
operation, no other dispatcher intervention is required until
the CD patch must be disconnected.
Audio connections between the CD and the CEC/IMC
are done inside the C3 Maestro's Audio Tower as controlled
by the Logic Board within the PC. The console's
application program running on the PC has minimal
involvement in the control of CD patch audio switching.
As with other telephone interconnect calls, CD patch
calls operate in the message trunked mode. From the
standpoint of the radio user, a CD patch operates
identically to any other telephone interconnect call.
CALL
DIRECTOR
C3
MAESTRO
AUDIO
TOWER
CEC/IMC
Figure 3 −− Basic Call Director Patch Audio Routing