7;5;6\VWHPV,QF
Manual 7-9547-1 12/09/14 Page 28
for future reference. Degradation levels in excess
of 1 to 2 dB should be investigated, as this will
decrease the range and performance of the sys-
tem.
ROUTINE OPERATION
During normal operation only one of the two tower
top amplifiers (“A” or “B”), and the base control unit
amplifier (“BASE”), are used to amplify the
received RF signals. The LED’s for the active
amplifiers will illuminate green. The remaining
tower-top amplifier will be in stand-by mode, which
is indicated by its LED being off. The system soft-
ware also provides an indication of which tower top
amplifier is active. From the default display use the
ARROW button to scroll down to the LNA X
ACTIVE menu which will display the currently
active tower top amplifier.
Upon power-up, the system defaults to operation
on the “A” tower top amplifier (the “BASE” amplifier
in the base control unit is always on). Operation
can be manually switched to the “B” tower top
amplifier by pressing the “B-SELECT” switch,
which is located below the “B-Status LED” on the
control unit front panel. The “B-Status LED” will
begin to flash, then press the ENTER button to
finalize the selection.
If necessary the system can be re-ini-
tialized via software interaction. From
the default display use the ARROW
button to scroll to the INITIALIZE
menu then press the ENTER button.
Amplifier Monitoring
The system continuously monitors the current
being drawn by the amplifiers and reveals the sta-
tus of the amplifiers in three ways: LCD Display,
front panel LED’s and Form-C contacts (“screw ter-
minals”).
LCD Display
The LCD display provides extensive status infor-
mation through the menu system including the cur-
rent draw of all amplifiers, connection of the test
transmission line, the tower top box temperature,
and installed software version level.
CURRENT DRAW
Typical displayed values for each of the system
amplifiers are listed in
Table 6
. The current value
for any amplifier can be read from the display by
using the ARROW buttons to scroll down from the
default display. The A and B tower top amplifiers
current draw are shown on one menu display and
the BASE amplifier current draw on another.
TTA TEMPERATURE
The temperature of the tower top box can be read
from the display by using the ARROW buttons to
scroll down from the default display to the TEM-
PERATURE sub-menu. The recommended normal
operating temperature range for the tower top box
is -30 to +60 degrees Celsius. The tower top ampli-
fier will function up to +70°C without shutting down.
However, the specifications are not guaranteed.
SOFTWARE VERSION
There are micro-controllers located in both the
tower top box as well as the base unit so there are
two software versions in the system. Both the
BASE and TOWER software version can be read
from the display by using the ARROW buttons to
scroll down from the default display to the SOFT-
WARE VERSION sub-menu.
Front Panel LEDs
Status indicator LED’s for all the amplifiers illumi-
nate in one of two colors; green for normal opera-
tion and red for alarm condition. During normal
operation, the LED’s for amplifier A and the BASE
amplifier will glow green, indicating normal current
draw. The LED for amplifier B will be off indicating
this amplifier is in stand-by.
Form-C Contacts
The ALARM Form-C relay contacts are located at
the back of the control unit. These terminals are
intended for connection to the customer’s supervi-
sory and data acquisition system. Both normally
open and normally closed contacts are available.
NOTE
Amplifier
Displayed Value
TTA Amp A
~440 mA
TTA Amp B
~440 mA
Base Amp
(MCU system only)
~980 mA
Table 6:
Typical current readings.
Note:
An inactive amp will show about 0 mA.
