Microair Avionics T2000UAV-L Transponder User Manual

3.3.1 STANDBY (S=T)
To bring the T2000UAV-L to the standby condition, the “s” parameter is set to the value “t”. Then the transponder can then be powered down. When the T2000UAV-L is restarted, it will return to standby
The transponder should be commanded to the standby condition when the vehicle is on the ground.
The transponder is typically set to mode 3A or mode 3A/C operation once airborne.
3.3.2 MODE 3A (S=A)
The T2000UAV-L transponder will respond to all mode A interrogations with the identity code set by the “c” parameter. The transponder will also reply to all mode C interrogations with just the framing pulse (no altitude data). This ensures visibility to TCAS operators, while the transponder is operating in mode A.
3.3.3 MODE C (S=C)
The T2000UAV-L will respond to all mode A interrogations with the identity code set by the “c” parameter, and all mode C interrogations with the encoder’s altitude data, as defined by the “a” parameter. The transponder will reply to both SSR and TCAS interrogations.
3.3.4 IDENT (I=S)
The ident function is performed at the request of ATC to “squawk ident”. To initiate the ident function the “i” parameter is set to s. The T2000UAV-L will switch to ident mode, which will add an additional data bit to the outgoing replies. The additional data bit makes the transponder return on the ATC display flash to assist the controller with identification. The transponder will remain in the ident mode for 18 seconds and then return to the previous mode of operation.
3.3.5 ALTITUDE (A=?)
The T2000UAV-L will reply with the current mode C value.
If the T2000UAV-L is configured to operate with an altitude encoder the T2000UAV-L will reply with the current barometric altitude from the encoder.
If the T2000UAV-L is configured to operate with a serial altitude data source, the T2000UAV-L will reply with the last received altitude data value.
3.3.6 ALTITUDE SOURCE (D=?)
The T2000UAV-L can accept altitude data for the mode C response either from a Gillham (d=g for 10-line parallel) source or from a serial (d=s for RS232) source.
When d=g is selected the T2000UAV-L will look to the 10-line Gillham input for data from an altitude encoder.
When d=s is selected the T2000UAV-L will look for altitude data to be passed via the “a” command on the RS232 serial data link. The altitude data source shall send the a= where the altitude value is between -1000 and 62000 feet, in increments of 100 feet. The altitude data source should issue this data report to the T2000UAV-L no slower than 1Hz.
Where the altitude data cannot be detected from the assigned source or the data cannot be encoded, no altitude data will be outputted. The mode C response will be framing pulses only. The T2000UAV-L will question the altitude data with a=?, via the RS232 serial interface.
3.3.7 ENCODER POWER (E=?)
When using an altitude encoder, it may be desirable to only have it powered up when the transponder is operating in mode C. This may save power, as most encoders will typically draw 125 to 150mA when operating.
The operator should allow up to 7 minutes for the encoder to “warm up” before valid altitude data is outputted from the encoder.
3.3.8 VOLTAGE OFFSET (F=?)
The voltage offset allows the user to calibrate the voltage function for accurate measurement of the bus voltage. The measured voltage is always less than the actual voltage. The offset value is adjusted to make the sum of measured volts and offset equal to the actual voltage.
3.3.9 VOLTAGE (V=?)
The T2000UAV-L will report the current vehicle bus voltage by polling the “v” parameter. To use this function operator must first set the reference bus voltage by setting v=1 for 14V operation, or v=2 for 28V operation.
The measured voltage is calibrated using the “f” command to offset an offset value. The measured voltage returned by the “v” command always has the current offset added.
3.3.10 REPLY ANNUNCIATOR (R=Y)
A conventional transponder normally has an annunciator of some type (typically a flashing LED) to indicate the rate of reply to SSR interrogations. This indication represents whether the transponder has made a reply to a “sweep”. The rotational speed of the radar is 100 deg/sec, hence the Annunciator should flash every 3.6 seconds.
The equivalent function for the T2000UAV-L is the “r” command which activates the reply annunciator.
When activated (r=y), the T2000UAV-L will send a single * character, if there was a reply made in the preceding 3.6 seconds. When not activated (r=n), no character is sent.
The operator can query the status of the reply annunciator function (r=?), and the T2000UAV-L will reply with the current functional state.
3.3.11 PING FUNCTION (P=?)
The ping function is a self-test of the RF sections of the transponder, without the need for a transponder test set. The T2000UAV-L will respond to the “ping” command (p=?) by emitting a narrow (invalid) pulse from the transmitter and detecting the same pulse back through the receiver.
If the T2000UAV-L is able to complete the transmission cycle, p=y is returned to the operator.
If the T2000UAV-L is not able to complete the transmission cycle, p=n is returned to the operator.
The ping function will only operate if the transponder is in mode a or c.
The ping function will not operate while the transponder is in standby mode.

T2000UAV-L TIE-DOWN STRAP

Microair recommends a simple tie-down strap, to hold the transponder in place. Drawing MA1156 shows the layout and use of a simple example.
Never use the case screws as part of the mounting system for the transponder. Always locate the strap over the chassis at a point that remains clear of the filter lock nuts.

Part Number: T2000UAV-L_MA1156_01R1-1

MODE C ENCODER

Mount the mode C blind encoder as per the manufacturer’s installation instructions. All wiring can be run back to the T2000UAV-L for connection (refer to wiring diagram). The power for the encoder is supplied from the T2000UAV-L. This power is switched when the T2000UAV-L is turned on.
IMPORTANT NOTE
Most encoder manufacturers advise of a warm-up period for their product before altitude data is supplied. The period can typically be up to 10 minutes. 

Where the OEM intends to use its own barometric altitude data source, it should comply with the TSO C88a standard, to be sure of compatibility with the T2000UAV-L.
Although it is unlikely that the encoder source in a UAV installation will require switched power from the T2000UAV-L, it is recommended that the ground be wired with the data lines in all cases. This will ensure the correct signal operation of the Gillham code.

ANTENNA

Mount the transponder antenna as per the manufacturer’s installation instructions. Try and keep the cable runs as short as possible. In a composite airframe, a suitable ground plane will be required. Avoid mounting the antenna inside a fuselage that is all metal or carbon fiber.
For fiberglass fuselages, the antenna may be mounted internally, but must still point downwards and have an adequate ground plane. Alternatively, an approved dipole strip antenna may be used. The dipole strip must be installed in accordance with the manufacturer’s instructions.
To avoid possible interference the antenna must be mounted a minimum of 200mm (8 inches) from the T2000UAV-L main unit. The transponder antenna should be mounted 2metres (78 inches) from the DME antenna, 1.5 meters (58 inches) from the ADF sense antenna, and 1metre (39 inches) from TCAS antennas.

COAXIAL CABLE

The T2000UAV-L allows for 1.5dB cable loss from the unit to the antenna. The installer should consider carefully what type of coaxial cable is to be used so that this loss limit is not exceeded. The cable should be terminated with silver-plated BNC connectors where possible.

Microair recommends the following:

Cable| Bending Radius| Loss @ 1Ghz
dB/m| Max Length| TX Power| RX Sensitivity
---|---|---|---|---|---
RG58/C/U
(Mil-Spec)| 50mm
(2”)| 0.76dB/m 0.21dB/ft| 2.0m
7ft| 142W| -70dBm
RG213/A/U
(Mil-Spec)| 125mm
(5”)| 0.26dB/m
0.08dB/ft| 5.75m
19ft| 142W| -70dBm
RG223/U
(Mil-Spec)| 100mm
(4”)| 0.47dB/m 0.14dB/ft| 3.2m
10ft| 142W| -70dBm
RG400
(Mil-Spec)| 50mm
(2”)| 0.60dB/m
0.18dB/ft| 2.5m
8ft| 142W| -70dBm
Belden 8262| 50mm
(2”)| 0.68dB/m 0.21dB/ft| 2.2m
7ft| 142W| -70dBm
URM-43| 50mm
(2”)| 0.47dB/m
0.14dB/ft| 3.2m
10ft| 142W| -70dBm

The loss figures in this table are a guideline only. When installed the power output at the antenna shall be greater than 125W and receiver sensitivity shall be better than -68dBm, to be compliant with RTCA/DO-144A.
IMPORTANT NOTE
Do not exceed the minimum bending radius. Tight bends will introduce losses in the cable, which may affect the performance of the transponder.
When fixing the coax cable in the airframe, do not “strangle” the cable with tight cable ties. This can distort or damage the coax screen. 

WIRING

The T2000UAV-L Transponder receives primary power (14V or 28V dc) from the aircraft’s power source. Power connections, voltage, and circuit breaker requirements are shown on the wiring diagram. The length of the power supply wires to parallel pins should be approximately the same length so that the best distribution of current can be affected.
It is very important to secure all D series plugs via their security screws before operation. Aircraft vibration may disconnect a D series plug if it is not secured.
Where possible, the antenna coaxial cable should be run separately to all other wirings on the aircraft from the transponder.
8.1 CABLING
Microair recommends that wiring for all of the T2000UAV-L’s functions and connections be run at the time of installation, even though they may not be required at this stage. Adding additional wiring to the loom at a later stage may be very difficult.
All wiring should be installed in accordance with FAA AC43.13-1A Chapter 11 or equivalent.
Microair recommends the following cable types for connection of the T2000UAV-L:

When terminating the DB plugs for connection to the T2000UAV-L, ensure that the wires are securely soldered to the pins and that each wire is separately insulated with heat shrink tubing.

The DB-25 plug is secured to the T2000UAV-L with machine screws or thumb screws. The DB-15 should also be secured to the encoder, either with screws, or a mechanical sliding lock (if fitted to some types of the encoder). If your encoder is fitted with a slide locking mechanism, the encoder manufacturer’s plug should be used, to ensure correct locking action.
8.2 POWER ON/OFF
The T2000UAV-L has no ON/OFF control function. The unit is on from the moment power is applied to the unit. There is no software OFF command. When power is removed from the T2000UAV-L, it will not respond to any software command.
When the T2000UAV-L is turned on, it is always in standby mode. The mode A code will default to the last mode A code used.
IMPORTANT NOTE
Always bring the T2000UAV-L to standby before turning off the power. If the transponder is powered off while it is in the process of transmitting, damage may occur to the internal power supply and/or the transmitter. Damage of this type is not covered by the warranty.
No mode C code will be outputted until the T2000UAV-L is supplied with altitude data (either serial or Gillham) which can be encoded by the transponder.
8.3 SUPPRESSION IN / OUT
The suppression IN line is wired to other avionics such as DME, to “suppress” the transponder’s transmissions, at times are critical to the other equipment’s operation.
The suppression OUT line does the reverse of the IN line. It is wired to other avionic equipment to allow the T2000UAV-L to “suppress” their transmissions at times critical to the T2000UAV-L’s operation.
Seek the advice of a qualified Avionics Technician before attempting to wire out these functions. If certified equipment is modified to operate in conjunction with the T2000UAV-L installation, then the installation of that equipment must be re-inspected and re-approved before operation.
8.4 EXTERNAL STANDBY
The external standby can be wired to a remote switch. When the line is taken to the ground the T2000UAV-L will return to standby mode and stay there regardless of the value for the “s” parameter. The “s” parameter cannot be queried while the external standby line is grounded.
Once the external standby line has been “released” from the ground, the T2000UAV-L will revert to the last “s” parameter setting.
8.5 EXTERNAL IDENT
Future development.

TECHNICAL DRAWINGS

WIRING DIAGRAMS

T2000UAV-L with EC2002 Altitude Encoder
T2000UAV-L with AK-350 Altitude Encoder
T2000UAV-L with A-30 Altitude Encoder
T2000UAV-L with serial altitude data interface

MICROAIR AVIONICS
T2000UAV-L TRANSPONDER
WIRING DIAGRAM
WITH EC2002 ALTITUDE ENCODER

MICROAIR AVIONICS
T2000UAV-L TRANSPONDER
WIRING DIAGRAM
WITH AK-350 ALTITUDE ENCODER

MICROAIR AVIONICS
T2000UAV-L TRANSPONDER
WIRING DIAGRAM
WITH A-30 ALTITUDE ENCODER

MICROAIR AVIONICS
T2000UAV-L TRANSPONDER
WIRING DIAGRAM
WITH SERIAL ALTITUDE DTA INPUT

PIN ASSIGNMENTS

The DB plugs for use with the T2000 series Transponders, require the following pin assignments.

SPECIFICATIONS

RTCA Compliance| DO-144A
DO-160D
DO-178B Level C
---|---
Transmitter| 1090MHz +/-0.2MHz
200W Pulse Output
80nS Rise Time
120nS Fall Time
Receiver| 0 to –71dBm Dynamic Range
1030MHz Centre Frequency
+/-3MHz Pass band @ -3dB
Input Power| 10-33Vdc
100-150mA @ 28V
150-200mA @ 14V
Operational Modes| Standby
Mode 3A (4096 codes)
Mode 3A/C
Temperature| -20° C to +55°C
Dimensions| Width     61mm
Height    61mm
Length   134mm
Weight| 454 g   (16 oz)

Specifications are subject to change without notice.

LIMITED WARRANTY

The warranty period for any Microair Avionics manufactured article is dependent on the Condition of the article at the time of sale and the Purchase Date.
For New Articles the warranty period commences from the Date of Purchase and is valid for one year or the minimum period defined by applicable consumer law, whichever is longer. In the absence of original Proof of Purchase, the warranty will be valid for two years from the Date of Factory Shipment as determined by Microair Avionics.
For Factory Reconditioned Articles offered for sale, the warranty period commences from the Date of Purchase and is valid for twelve months.
For Factory Exchanged Articles the warranty period commences from the Date of Purchase of the original article and is valid for the remainder of the original warranty period.
For Repaired Articles, the warranty period commences from the date of Factory Shipment and is valid for 6 months for the original defect only.
Microair Avionics will, at its sole discretion, repair or replace any components, which fail in normal use. Such repairs or replacements will be made at no charge to the customer for parts or labor. The customer shall be responsible for any transportation costs for the return of this product to Microair Pty Ltd or an approved Microair Service Centre.
This warranty does not cover failures due to abuse, misuse, accident, unauthorized alteration, or repairs carried out by parties other than Microair Avionics or an approved Microair Avionics Service Centre. This warranty does not cover failures where the product has not been installed or operated, in accordance with the provisions of the User and Installation manual(s).
It shall be at Microair Avionics’ sole discretion to decide if a defect is a result of material or workmanship failure.
THE WARRANTIES AND REMEDIES CONTAINED HEREIN ARE EXCLUSIVE AND IN LIEU OF ALL OTHER WARRANTIES EXPRESSED OR IMPLIED, INCLUDING ANY LIABILITY ARISING UNDER WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, STATUARY, OR OTHERWISE. THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, WHICH MAY VARY FROM STATE TO STATE, AND COUNTRY TO COUNTRY.
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Microair Avionics may at its discretion, refer product returns for repair or service, to a service facility closest to you. Microair Avionics reserves the right to repair or replace the product or software or offer a full refund of the purchase price at its sole discretion.
To obtain warranty service, please email or call the Microair Avionics Repair line in Australia.
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