2 . 1 2
ICS TIE AND ICS KEYING
The ICS Bus is a bidirectional audio line allowing connection of multiple intercom systems and
panels in one installation. This can be achieved simply by connecting together all of the ICS Bus
signals of all the devices.
PLEASE NOTE:
In installations where separate ICS keying for the passengers is not possible, the PAX ICS
Keying line must be connected to ground for the intercom to work with the VOX knob in the
keyed (fully counter-clockwise) position.
See Table 2-l
(50 pin “D”). See also connection diagram
Figure 2-3.
2 . 1 3
BACKLIGHTING POWER + 28VDC / + 5VDC
The backlighting power for the front panel of the TAC-200A is supplied via pin 3 of the 50pin
connector for +28VDC, and pin 2 of the 50 pin connector for +5VDC. Do NOT supply more
than + 5VDC (-15% + 15%).Unless ordered and indicated otherwise on the rear of the TAC-
200A, the unit is shipped with the +28VDC backlighting option.
See Table
2-1 (50 pin "D”). See also connection diagram
Figure 2-3.
2.14 GROUND
The TAC-200A Audio Controller is designed for optional Ground Isolation from the Airframe.
This is necessary in some cases where the Airframe Ground might cause noise in the Audio
system. The TAC-200A is factory configured for Isolation. Despite the nomenclature, all ground
lines are common. If ground isolation is not required or desired, the ground isolation jumpers
may be connected.
See Figure
2-5 for location of ground isolation jumpers.
Main ground to the Audio Controller is on pin #34 of the 50 pin “D” connector. All other
grounds are common to this and are on pins #1, #35 - #44, #46 - #50 these GROUND
connections are depicted as shaded cells in
Table 2-l.
Ground connections on the 37 pin “D” connector are on pins #4, #20, #22 - #30, and #33 -
#37. These GROUND connections are depicted as shaded cells in
Table 2-2.
Ground connections on the 15 pin “D” connector are on pins #6, #9 - #I 1, and #14 - #15.
These GROUND connections are depicted as shaded cells in
Table 2-3.
2-9
