Garrecht Avionik GmbH
VT-01 Transponder
Installation Manual - english -
Document:
01.0200.11E
Revision: 1.3
18
6.1.4.2. Power supply
The transponder is supplied by the aircrafts’s primary power source (10 V to 28 V DC). The system
provides protection against reverse polarity.
Always install a Fuse !!!
6.1.4.3. Suppression interface
The suppression line needs to be wired to other avionic components working in the 962..1213 MHz
frequency band, such as DME or TACAN, to suppress any replies from the transponder that void the
capabilty of such systems while operating.
The suppression line provides IN and OUT capability to prevent data transmission either to the
transponder or other equipment.
Wiring the suppression line requires a qualified avionic technician or
engineer to prevent any kind of malfunction of the installed equipment. All
equipment connected to the suppression line must be re-inspected and re-
approved before operation. Refer to chapter 5 for specifications of the
suppression interface.
6.1.4.4. On-ground interface
If your aircraft installation provides an on-ground signal, it should be connected to this pin. The
tranponder replies only to discretely addressed Mode-S interrogations if the on-ground signal is
present. The permament emission of squitters will not be effected.
Refer to chapter 5.10 for logic table of this interface.
6.1.4.5. RS-232 interface
This interface is intended for ADS-B applications. It may be used for connecting a GPS receiver to
broadcast the current position with extended squitters.
Minimum recommended NMEA sentences are $GPRMC, $GPGGA, $GPGSA. The baud rate is 4800
bps.
6.1.4.6. CAN-Bus interface
The CAN-Bus interface is used for communication between steering unit and
central unit. If the one-block configuration will be installed, a resistor (100
ohms) must be used for proper termination of the bus. A missing termination
results in COMM error and malfunction of the system.
For pinout refer to the wiring diagram shown on the previous page.
6.1.4.7. Antenna connection
Connect the BNC plug of the antenna line to the connector in the back of the central unit. Be sure that
the plug has been fastened to prevent disconnection caused by vibration
DO NOT POWER ON THE TRANSPONDER WITH THE ANTENNA
DISCONNECTED !!!
Damage to the RF unit caused by a disconnected antenna can be
determined by the manufacturer and is not covered by the manufacturers warranty.
Refer to chapter 9 for details about installing a transponder antenna in your aircraft.
