User's Manual

AT7120 Owner Manual Rev. 1.1 – March 2009 21/76
In the absence of this signal, the power supply - Module 4401 - will stop supplying the +32 volt line,
which feeds the 60W UHF amplifier - Module 4407. The other voltages remain present if the transmitter
is operational.
Serial communication RS232
The access to CIP8231 board is through a PC that has the Windows Hyper Terminal. At the rear panel of
the transmitter there is a DB9 connector - tag as RS232- which is linked to connector CON-10, located
at CIP8231 board.
Keypad – CIP8002 board
The CIP8002 board contains five key buttons SW1 to SW5, located on the front panel of the transmitter.
This board is a matrix of electrical ON/OFF contacts. The responses are made available at the connector
CON-3.
LCD - CIM3004 board
CIM3004 board is a LCD - Liquid Crystal Display - of 20 columns by 2 lines. The back light of this
display is controlled by the CIP8231 board which sends +5V between a test point termed A+ (yellow
wire) and ground test point termed K- (white wire). The trimpot TPO-1 located at CIP8231 board
controls the intensity of the characters of the display. The jumper J1, also located at CIP8231 board, can
be set to the R61 position, if the LCD back light is desired to stay ON at all time.