______________________________________________
HARRIS
888-9058-001
WARNING: Disconnect and lockout AC primary power prior to servicing
154
commands to and from the individual boards to light the correct LEDs. It is also
responsible for detecting if a key is pressed and sending the information to the correct
board. The switch panel provides a local user interface that is an alternative or backup to
using the touchscreen. It provides a means to decode pressed button information and then
send the decoded information on to the various controllers for them to determine what
needs to be done. The controllers will then send back information that will determine
what button/indicator are to be lit, and what color. In event of a CAN bus error, this
panel in the driver cabinet becomes the operating controls at the transmitter. The switch
panels are capable of turning the transmitter on and off, but no transmitter information
will be given. This is possible because each PA cabinet control board is capable of
operating and protecting its own area. Each of the control boards only need to get on/off
commands from the switch panel. The system bus provides additional parallel lines
which pass critical information such as parallel remote control.
6.3.4 Display Unit
The display unit is an eCDi system with CAN bus capability and a GUI interface added.
eCDi™ is a transmitter network interface appliance that provides a network connection
for control and monitoring of Harris transmitters that have a serial connection port. For
the Platinum-I, this includes a local GUI touchscreen interface in addition to its normal
networking capabilities. This becomes the local transmitter control interface using the
attached 12" VGA touchscreen and has been named the “Display Unit.” This means that
the eCDi™ provides both local and remote control for the Platinum-i transmitter. For
more information refer to the control section of the manual, Section 5.
6.4 Accessory Tray
6.4.1 Exciter Switcher (Drwg: 843-7900-228)
The exciter switcher consists of two sections: the logic, which is mounted in the
accessory tray above the exciters, and the relay panel which is mounted in the cabinet on
the back of the hinged door above the accessory tray. (Refer to the exciter switcher logic
board and relay panel schematics). The vision and sound RF outputs of each exciter is
detected, and the detected DC samples are routed to the exciter logic board. When the
switcher is in “Automatic” mode; if the vision or sound output samples drop below a
preset threshold, the logic board signals the relay panel to switch to the other exciter.
However, this switching action will only occur if the second exciter’s outputs are above
their preset threshold. These threshold controls are marked SET on the front of the
switcher logic panel. In Manual mode, either exciter may be selected regardless of its
vision and sound output levels. LEDs indicate Automatic mode, exciter A or B active,
and faults (output below threshold) on exciter A or B. The relay panel also switches the
I/O paths between the main controller and exciters. Commands from the control system
are routed to the active exciter.
