Becker RT6512-100 Guide

Becker Avionics GmbH •Baden-Airpark B108 •77836 Rheinmünster •Germany
+49 (0) 7229 / 305-0 •Fax [phone] / 305-217
http://www.becker-avionics.com •E-mail: [e-mail]
Remote-Controlled
VHF-AM Transceiver
RT6512
RT6512-(100)
RT6512-(200)
RT6512-(201)
Installation and Operation
Manual DV17501.03
Issue 05 May 2017
Article-No. 0645.702-071

Installation and Operation
2 RT6512 DV17501.03 Issue 05 May 2017
WARNING - USER RESPONSIBILITY
FAILURE OR IMPROPER SELECTION OR IMPROPER USE OF THE PRODUCTS DESCRIBED
HEREIN OR RELATED ITEMS CAN CAUSE DEATH, PERSONAL INJURY AND PROPERTY
DAMAGE.
•This document and other information from Becker Avionics GmbH provide product or system
options for further investigation by users having technical knowledge.
•The user is responsible for making the final selection of the system and components. The user
has to assure that all performance, endurance, maintenance, safety requirements of the
application are met and warnings be observed.
For this the user has to include all aspects of the application to be compliant with the applicable
industry standards and the requirements of the responsible aviation authority. The product
documentations from Becker Avionics GmbH have to be observed.
•To the extent that Becker Avionics GmbH provide component or system options based upon data
or specifications provided by the user, the user is responsible for determining that such data and
specifications are suitable and sufficient for all applications and reasonably foreseeable uses of
the components or systems.
Term definition: User in the sense of user, installer, installation company.

Installation and Operation
DV17501.03 Issue 05 May 2017 RT6512 3
Preface
Dear Customer,
Thank you for purchasing a Becker Avionics product. We are pleased that you have chosen our
product and we are confident that it will meet your expectations.
For development of our products, the guidelines for highest quality and reliability have been borne in
mind, supplemented by selection of high quality material, responsible production and testing in
accordance to the ISO 9001 and DIN EN 9100 standards.
Our competent customer support department will respond on any technical question you may have.
Please do not hesitate to contact us at any time.
Remote
- Controlled VHF-AM Transceiver
RT6512
(Remote Transceiver)

Installation and Operation
4 RT6512 DV17501.03 Issue 05 May 2017
List of Effective Pages and Changes
Only technical relevant modifications are described in this table.
Document: DV17501.03 / issue 05 Article Number 0645.702-071
Cover Page 05/2017
Introduction 05/2017
Chapter 1 – 4 05/2017
Issue Page No.: Section /
Chapter Description
05 1-60 all Changed: Editorial adjustments.
-- 1.5.3 Updated: Descriptions Emergency Mode
-- 2.3.4 Added: More detailed "Antenna Installation"
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© 2017 by Becker Avionics GmbH / all rights reserved

Installation and Operation
DV17501.03 Issue 05 May 2017 RT6512 5
Table of Contents
1. General Description .................................................................................................................... 11
1.1. Introduction.................................................................................................................................. 12
1.2. Purpose of Equipment................................................................................................................. 13
1.3. Variants Overview....................................................................................................................... 13
1.4. Associated Devices..................................................................................................................... 13
1.5. Scope of Functionality................................................................................................................. 14
1.5.1. Receive Mode................................................................................................................... 14
1.5.2. Transmit Mode.................................................................................................................. 14
1.5.3. Emergency Mode.............................................................................................................. 14
1.5.4. Audio Inputs and Outputs ................................................................................................. 15
1.5.4.1. Microphone Input................................................................................................... 15
1.5.4.2. Audio Input LINE IN............................................................................................... 15
1.5.4.3. Audio Output LINE OUT........................................................................................ 15
1.5.5. Control Inputs.................................................................................................................... 16
1.5.5.1. /ON (Unit Power ON/OFF Control)........................................................................ 16
1.5.5.2. /PTT (Push-To-Talk).............................................................................................. 16
1.5.5.3. /COM2 (Com Addressing Line) ............................................................................. 16
1.5.5.4. /SEL422 (Serial Interface Selection Line) ............................................................. 16
1.5.5.5. /RX_ATT (External RX Attenuation Control)......................................................... 16
1.5.5.6. /SERV_EN (Enabling the Setup Modes)............................................................... 17
1.5.5.7. /TX-ENABLE (Enabling the TX) ............................................................................ 17
1.5.5.8. /EMERG (Enabling the Emergency Mode)............................................................ 17
1.5.6. Status and Control Outputs .............................................................................................. 18
1.5.6.1. /FAILURE............................................................................................................... 18
1.5.6.2. RX_AGC (AGC Voltage of the RX-RF-AGC)........................................................ 18
1.5.6.3. /SQL_EVAL ........................................................................................................... 18
1.5.7. Digital Interfaces to the Control Unit................................................................................. 19
1.5.7.1. Interface ARINC 429 ............................................................................................. 19
1.5.7.2. Interface RS422..................................................................................................... 19
1.6. Safety-Conscious Utilization ....................................................................................................... 20
1.7. Restriction for Use....................................................................................................................... 20
1.8. Technical Data ............................................................................................................................ 21
1.8.1. General Characteristics .................................................................................................... 21
1.8.2. Typical Power Consumption............................................................................................. 21
1.8.3. Receiver Data ................................................................................................................... 22
1.8.4. Transmitter Data............................................................................................................... 23
1.8.5. Dimensions & Weight........................................................................................................ 23
1.8.6. Software............................................................................................................................ 24
1.8.7. Hardware .......................................................................................................................... 24
1.8.8. Continued Airworthiness................................................................................................... 24
1.8.9. Environmental Conditions................................................................................................. 25
1.8.10. Certifications ..................................................................................................................... 26
1.8.10.1. RT6512 Certification.............................................................................................. 26
1.8.10.2. RT6512 meets the Requirements of: .................................................................... 26
1.8.10.3. Guidelines followed for Design and Development ................................................ 26
1.8.10.4. FCC Approval........................................................................................................ 27
1.9. Order Code.................................................................................................................................. 28
1.9.1. RT6512 ............................................................................................................................. 28
1.9.2. Accessories....................................................................................................................... 28
2. Installation.................................................................................................................................... 29
2.1. Packaging, Transport, Storage ................................................................................................... 29
2.2. Device Assignment ..................................................................................................................... 30
2.2.1. Scope of Delivery.............................................................................................................. 30
2.2.2. Additional Required Equipment (optional)........................................................................ 30
2.2.3. Type Plate......................................................................................................................... 31
2.2.4. Meaning of Status LEDs................................................................................................... 31

Installation and Operation
6 RT6512 DV17501.03 Issue 05 May 2017
2.3. Mounting Requirements ..............................................................................................................32
2.3.1. Mounting Distance ............................................................................................................32
2.3.2. Grounding..........................................................................................................................32
2.3.3. Antenna Cables.................................................................................................................33
2.3.3.1. Attenuation: Cable length versus coax cable type.................................................33
2.3.4. Antenna Installation...........................................................................................................34
2.3.4.1. Required Antenna Type.........................................................................................34
2.3.4.2. Antenna Mounting Location...................................................................................34
2.3.4.3. Recommendation for Installation of two RT6512 in one Aircraft...........................36
2.3.4.4. Radio Setting and Wiring for dual installation........................................................36
2.4. Dimensions..................................................................................................................................37
2.4.1. RT6512..............................................................................................................................37
2.4.2. RT6512 with Mounting Tray MT6512................................................................................38
2.5. Connector Pin Assignments........................................................................................................39
2.5.1. Connector P1 (RT6512)....................................................................................................39
2.6. Equipment Configuration Samples..............................................................................................41
2.6.1. RT6512 with RMU5000.....................................................................................................41
2.6.2. RT6512 with ARINC 429 Controller..................................................................................41
2.7. Aircraft Wiring..............................................................................................................................42
2.7.1. RT6512-(XX0) with ARINC 429 Controller........................................................................43
2.7.2. RT6512-(XX1) with ARINC 429 Controller........................................................................44
2.8. Post Installation Tests .................................................................................................................45
2.8.1. Mechanical Installation and Wiring Check ........................................................................45
2.8.2. Power Supply....................................................................................................................45
2.8.3. Receiver / Transmitter Operation......................................................................................45
2.8.4. Antenna Check..................................................................................................................45
2.8.5. Interference Check............................................................................................................45
2.8.6. Flight Test Check ..............................................................................................................47
3. Operating Instructions................................................................................................................49
3.1. Device Description.......................................................................................................................49
3.1.1. Device Assignment ...........................................................................................................49
3.2. Operating with RMU5000............................................................................................................49
3.3. Operating with OEM Controller ...................................................................................................49
3.4. Start-Up .......................................................................................................................................50
3.4.1. Built In Tests (BIT) ............................................................................................................50
3.4.1.1. Initiated Built In Test (IBIT)....................................................................................52
3.4.1.2. Power On Built In Test (PBIT) ...............................................................................52
3.4.1.3. Continuous Built In Test (CBIT).............................................................................52
3.4.1.4. Error Indication.......................................................................................................53
3.5. ARINC 429 Protocol supported by RT6512 ................................................................................55
4. Index..............................................................................................................................................60

Installation and Operation
DV17501.03 Issue 05 May 2017 RT6512 7
List of Figures
Figure 1 Standard Microphone Input Schematic....................................................................................................15
Figure 2 LINE_IN Schematic..................................................................................................................................15
Figure 3 LINE_OUT...............................................................................................................................................15
Figure 4 /FAILURE Output Schematic...................................................................................................................18
Figure 5: Type Plate (Example) .............................................................................................................................31
Figure 6:RT6512 with MT6512 - mounting area.....................................................................................................32
Figure 7: Antenna Installation................................................................................................................................34
Figure 8: RT6512 Dimensions (without and with Main Connector applied)............................................................37
Figure 9: RT6512 with Mounting Tray MT6512......................................................................................................38
Figure 10: RT6512 with RMU5000.........................................................................................................................41
Figure 11: RT6512 with ARINC 429 Controller......................................................................................................41
Figure 12: RT6512-(XX0) with ARINC 429 Controller............................................................................................43
Figure 13: RT6512-(XX1) with ARINC 429 Controller............................................................................................44
Figure 14 Thermal Behavior for TX Function.........................................................................................................51
List of Abbreviations
List of Abbreviations
A3E
Amplitude modulation double-sideband with full carrier
AGC
Automatic Gain Control
AM
Amplitude Modulation
AOC
Air Operations Centre
ARINC
Aeronautical Radio Incorporated
ARINC 429
Data bus for commercial aircraft
ATS
Air Traffic Services
BIT
Built In Test
BNC
Bayonet Neill Concelman (connector)
CBIT
Continuous Built In Test
CU
Control Unit
DAL
Design Assurance Level
DC
Direct Current
EUROCAE
European Organization for Civil Aviation Equipment
EASA
European Aviation Safety Agency
FAA
Federal Aviation Administration
IBIT
Initiated Built In Test
n/a
not applicable
LED
Light Emitting Diode
OEM
Original Equipment Manufacturer
PBIT
Power On Built In Test
PSB
Power Supply Board
PTT
Push To Talk
RCU
Remote Control Unit
RMU
Radio Management Unit
RX
Receiver
Std
Standard
TX
Transmitter
VDC
Volts Direct Current
VHF
Very High Frequency

Installation and Operation
8 RT6512 DV17501.03 Issue 05 May 2017
List of Abbreviations
VSWR
Voltage Standing Wave Ratio
Units
Units
A
Ampere
mA
Milliampere
°C
Degree Celsius
dBm
Power ratio in Decibel
dB
Decibel
ft
Foot
g
Gram
in
Inch
kHz
Kilohertz
MHz
Megahertz
mm
Millimeter
NM
Nautical Mile
kΩ(kilo Ohm)
Resistance kilo Ohm
Ohm (Ω)
Resistance
ppm
Part per million
s
Second
V
Volt
mV
Millivolt
W
Watt
mW
Milliwatt
General Safety Instructions
Indicates a hazardous situation which, if not avoided, will result in death or serious
injury.
Indicates a hazardous situation which, if not avoided, could result in death or
serious injury.
Indicates a hazardous situation which, if not avoided, could result in minor or
moderate injury.
Is used to address practices not related to physical injury.
Safety instructions (or equivalent) signs indicate specific safety-related
instructions or procedures.

Installation and Operation
DV17501.03 Issue 05 May 2017 RT6512 9
Disposal
The packaging material is inflammable, if it is disposed of improperly by
burning, toxic fumes may develop.
This product contains materials that fall under the special disposal regulation, which corresponds to
the EC directive for dangerous disposal material. We recommend disposing of the respective materials
in accordance with the respectively valid environmental laws. The following table states the materials
suitable for recycling and the materials, which have to be disposed of separately.
Material
Suitable for recycling
Disposal
Metal
yes
no
Plastics
yes
no
Circuit boards
no
yes
Dispose of the circuit boards:
•Disposal via a technical waste dump, which is allowed to take on e.g. electrolytic
aluminium capacitors. Do under no circumstances dump the circuit boards with normal
waste dump.
Warranty Conditions
The device(s) may be installed only if further evaluation by the user/installer
documents an acceptable installation that is approved by the appropriate
airworthiness authority.
User Conversions and Changes are Not Permitted.
Any change on the product, made by the user, excludes any liability of Becker Avionics GmbH.
•For installation, opening the device is not required.
•Do not make any modifications to the device, except for those described in the manual.
•Make connections to the inputs, outputs and interfaces only in the manner described in
the manual.
•Install the devices according to the instructions.
We cannot provide any guarantee for other mounting methods.
Conditions of Utilization
General introductory notes
With this device you bought a product, which was manufactured and tested before delivery with the
utmost care.
Please take your time to read the following notes, which you should follow closely during installation
and operation. Otherwise, all claims under the warranty will become void and a reduced service life or
even partial damage is not excludable.
The user is responsible for a safe installation and/or additional safety measures
in order to prevent damages to persons or the electric installations of the
airplane. In case of deviations to the descriptions in this document perform all
work in accordance with the airplane service manual or take the AC43-13, in its
latest revision, into account.
Additional Conditions of Utilization
Please refer to "Safety-Conscious Utilization", page 20.
Non-Warranty Clause
We checked the contents of this publication for compliance with the associated hard and software. We
can however, not exclude discrepancies and do therefore not accept any liability for the exact
compliance. The information in this publication is undergoing a regularly review, necessary corrections
will be part of the subsequent issues of this publications.

Installation and Operation
10 RT6512 DV17501.03 Issue 05 May 2017
Blank Page

General Description
Introduction
DV17501.03 Issue 05 May 2017 RT6512 11
1. General Description
In this chapter you can read about:
1.1. Introduction.................................................................................................................................. 12
1.2. Purpose of Equipment................................................................................................................. 13
1.3. Variants Overview....................................................................................................................... 13
1.4. Associated Devices..................................................................................................................... 13
1.5. Scope of Functionality................................................................................................................. 14
1.5.1. Receive Mode................................................................................................................... 14
1.5.2. Transmit Mode.................................................................................................................. 14
1.5.3. Emergency Mode.............................................................................................................. 14
1.5.4. Audio Inputs and Outputs ................................................................................................. 15
1.5.5. Control Inputs.................................................................................................................... 16
1.5.6. Status and Control Outputs .............................................................................................. 18
1.5.7. Digital Interfaces to the Control Unit................................................................................. 19
1.6. Safety-Conscious Utilization ....................................................................................................... 20
1.7. Restriction for Use....................................................................................................................... 20
1.8. Technical Data ............................................................................................................................ 21
1.8.1. General Characteristics .................................................................................................... 21
1.8.2. Typical Power Consumption............................................................................................. 21
1.8.3. Receiver Data................................................................................................................... 22
1.8.4. Transmitter Data............................................................................................................... 23
1.8.5. Dimensions & Weight........................................................................................................ 23
1.8.6. Software............................................................................................................................ 24
1.8.7. Hardware .......................................................................................................................... 24
1.8.8. Continued Airworthiness................................................................................................... 24
1.8.9. Environmental Conditions................................................................................................. 25
1.8.10. Certifications ..................................................................................................................... 26
1.9. Order Code.................................................................................................................................. 28
1.9.1. RT6512 ............................................................................................................................. 28
1.9.2. Accessories....................................................................................................................... 28
The mechanical design of the remote-controlled VHF-AM transceiver RT6512 is ruggedized and well
suited for installation in the avionics compartment (non-pressurized and not temperature controlled) by
means of a mounting plate and in all types of aircraft.
The remote controlled VHF-AM transceiver RT6512 meets RTCA and EUROCAE airworthiness
requirements applicable at the time the unit received certification. There are no restrictions for
installation of the unit as long as it will be installed in areas, where data of the proven environmental
categories will not exceed.

General Description
Introduction
12 RT6512 DV17501.03 Issue 05 May 2017
1.1. Introduction
The technical information in this manual mainly applies to all variants of the described product.
Therefore, we name the product generally with "RT6512" when descriptions are not unique for a
product variant. If a description refers to only one of the product variants its full name, e.g.
"RT6512-(100)", will be used.
The manuals Maintenance & Repair (M&R), Installation & Operation (I&O) contain the following
sections:
Section DV 17502.04
M&R DV 17502.03 I&O
General Description X X
Installation X X
Operation Instructions X X
Theory of Operation X N/A
Maintenance and Repair X N/A
Illustrated Parts List X N/A
Modification and Changes X N/A
Circuit Diagrams X N/A
Certifications X N/A
Attachments X N/A

General Description
Purpose of Equipment
DV17501.03 Issue 05 May 2017 RT6512 13
1.2. Purpose of Equipment
•RT6512 is a simplex voice communication system in the standard avionics VHF frequency
range 118.000...136.975 MHz (136.9916 MHz with 8.33 kHz channel spacing), or optional
with extended frequency range up to 155.975 MHz and uses standard amplitude
modulation (A3E). RT6512 is capable to operate in both, the 25 or 8.33 kHz channel
spacing, is primarily intended for aeronautical operational control (AOC) and air traffic
services (ATS) safety communications.
•RT6512 uses ARINC 429 and RS422 interfaces for communication with a control device.
•RT6512 provides frequency and mode control, either by means of the Becker RMU5000
controller using the RS422 communication port, or by means of any OEM product using
the standard ARINC 429 communication bus.
•With transmitter power of 20W, RT6512 is able to support simultaneous communication
over a range exceeding 200 NM direct line of sight, within the frequency range.
1.3. Variants Overview
Within the part number, the meaning of "RT6512-(XXX)", is:
RT
6512
-
(
X
X
X
)
Type Identifier
0 – Standard
1 – with Emergency Mode
Model Number
0 - Standard
1 – Std. Freq. Range 118...136.975 MHz
2 – Ext. Freq. Range 118...155.975 MHz
1.4. Associated Devices
Following devices can operate with RT6512-(XXX):
Device
Function/Manufacturer
RMU5000
Becker Avionics Radio Management Unit
Control unit
Gables G7610 (Control unit for VHF-COMM only)
Control unit
Universal RCU
Glass cockpit
Genesys IDU680

General Description
Scope of Functionality
14 RT6512 DV17501.03 Issue 05 May 2017
1.5. Scope of Functionality
RT6512 performs AM (amplitude modulation) voice communication.
Mechanics: Case serves as heat sink mount it proper as defined in chapter "", page 32.
Front side contains the main connector (D-Sub 37pin, male) for connection to the aircraft wiring
system, and the antenna jack (BNC, female).
The green LED indicates the system is operable. The yellow and red LED indicates that a warning or
failure has occurred (refer to "Status & Error Indication", page 53).
1.5.1. Receive Mode
RT6512 is equipped with a high quality Class C, E and H2 receiver: standard sensitivity 5 µV, high
dynamic range, and high blocking rejection. It can receive a weak signal while a 2nd VHF-
AM transceiver in the same aircraft is transmitting. The RT6512 can operate with offset carrier in both
25 kHz and 8.33 kHz channel spacing.
1.5.2. Transmit Mode
RT6512 is equipped with a high quality Class 3 and 5 transmitter: output power of 20 W under
standard operating conditions, output power of at least 16 W under the specified environmental
operating conditions (when using antenna with VSWR=≤2:1, for VSWR>3:1 output power lowers),
AM depth >70% - standard value for airborne application.
During transmission, the transmitter delivers a natural sidetone signal, which is available on the
LINE_OUT output (if enabled).
RT6512 is equipped with a protective function to prevent from blocking the frequency channel by a
stuck transmit button or a short circuit on the key line. "Stuck PTT" time is set to 30 seconds.
RT6512 provides status information if device is transmitting via serial protocol (RS422 and
ARINC429). This status can be used to inform the crew about terminated transmission (as required by
TSO-C128a/ETSO-2C128).
RT6512 transmitter is protected from overheating. VSWR on Antenna connector is also monitored.
See "Status and Control Outputs", page 18 for details.
1.5.3. Emergency Mode
The RT6512-(201) variant supports Emergency Mode in which device is automatically tuned to
emergency channel 121.500 MHz in 25 kHz channel spacing. External control of transceiver is
prohibited with remaining device status monitoring.
Note:Operators Remark
121.5 MHz = International voice aeronautical emergency.
123.1 MHz = International worldwide voice SAR use (e.g. Italy).

General Description
Scope of Functionality
DV17501.03 Issue 05 May 2017 RT6512 15
1.5.4. Audio Inputs and Outputs
1.5.4.1. Microphone Input
Figure 1 Standard Microphone Input Schematic
RT6512 is designed for a standard microphone:
•Unbalanced,
•DC coupled,
•DC suppliedfrom RT6512.
The bias current for standard microphone is drawn from RT6512 internal source 15 VDC via series
resistor 470 Ohm. The input audio signal is routed to a dynamic compressor keeping the modulation
factor limited over a wide input voltage range. The microphone input uses the cable guard as ground
compensation so microphone input shall be connected exactly as specified on Installation diagrams.
1.5.4.2. Audio Input LINE IN
Figure 2 LINE_IN Schematic
The RT6512 symmetrical line input has no DC connection to ground. Input impedance is 600 Ω. The
maximum input level without clipping can be set as high as 6 V. The input audio signal is routed to a
dynamic compressor keeping the modulation factor limited over a wide input voltage range.
1.5.4.3. Audio Output LINE OUT
Figure 3 LINE_OUT
The audio output LINE OUT design is symmetrical and has no DC connection to ground. If volume set
to maximum, the audio output power delivered is 100…125 mW into 600 Ωor 200 mW into 150 Ω.

General Description
Scope of Functionality
16 RT6512 DV17501.03 Issue 05 May 2017
1.5.5. Control Inputs
1.5.5.1. /ON (Unit Power ON/OFF Control)
/ON signal to switch ON/OFF the RT6512.
The /ON line is used to activate an internal electronic switch to power-up the unit.
It is active if the level on the /ON pin is less than 4.0 V or a resistance of less than 1 kΩconnects to
ground.
The /ON line is inactive if the level on the /ON pin is higher than 8.0 V or a resistance higher
than 50 kΩ connects to ground.
1.5.5.2. /PTT (Push-To-Talk)
/PTT is used to initiate transmission.
It is active when /PTT-input level is below 4.0 V, or a resistance to ground of less than 1 kΩ.
The /PTT line is inactive if the level on the /PTT-input is higher than 8.0 V, or a resistance higher
than 50 kΩconnects to ground.
1.5.5.3. /COM2 (Com Addressing Line)
/COM2 defines device sub address for ARINC communication.
The device detects a LOW state (Active state) on the /COM2 input when an external resistance of
lower than 1 kΩ is connected to ground.
The device detects a HIGH state (Inactive state) on the /COM2 input when an external resistance of
higher than 50 kΩ is connected to ground.
•Com addressing line bit:
oLOW (Active) state selects COM2.
oHIGH (Inactive) state selects COM1.
1.5.5.4. /SEL422 (Serial Interface Selection Line)
/SEL422 selects RS422 or ARINC 429 communication.
The device detects a LOW state (Active state) on the /SEL422 input when an external resistance of
lower than 1 kΩ is connected to ground.
The device detects a HIGH state on the /SEL422 input when an external resistance of higher
than 50 kΩ is connected to ground.
•Serial interface selection line:
oLOW (Active) state selects RS422.
oHIGH (Inactive) state selects ARINC.
1.5.5.5. /RX_ATT (External RX Attenuation Control)
/RX_ATT reduces the RF gain of the RX section to reduce cross talk effects.
The /RX_ATT line is used for an optional desensitization of the RT6512 receiver. The desensitization
can be required when a 2nd VHF-AM transceiver in the same aircraft is transmitting. In such case /PTT
line from 1st VHF-AM transceiver shall be connected to /RX_ATT input of 2nd device and /PTT from 2nd
device shall be connected to /RX_ATT input of the 1st device.
The /RX_ATT is active if /RX_ATT-input level is less than 4.0 V, or a resistance less than 1 kΩ
connects to ground.
The /RX_ATT line is inactive if the level on the /RX_ATT-input is higher than 8.0 V, or a resistance
higher than 50 kΩ connects to ground.

General Description
Scope of Functionality
DV17501.03 Issue 05 May 2017 RT6512 17
1.5.5.6. /SERV_EN (Enabling the Setup Modes)
/SERV_EN enables the setup modes.
/SERV_EN is a read/write access for all setup data, not available for standard user
The device detects a LOW state (Active state) on the /SERV_EN input when an external resistance of
lower than 1 kΩ is connected to ground.
The device detects a HIGH state (Inactive state) on the /SERV_EN input when an external resistance
of higher than 50 kΩ is connected to ground.
1.5.5.7. /TX-ENABLE (Enabling the TX)
/TX-ENABLE enables the transmitter.
RT6512 detects a low state on the /TX_ENABLE input when an external resistance lower than 1 kΩ
connects to ground.
RT6512 is detecting high state on the /TX_ENABLE input when an external resistance higher
than 50 kΩ connects to ground. In such case transmission is permanently blocked.
For an aircraft installation /TX-ENABLE input shall be connected to ground
directly on the main connector. /TX-ENABLE line cannot be routed as part
of installation cable bundle.
Note: Do not apply DC voltage above 5 Volts to /TX_ENABLE to avoid
device damage!
1.5.5.8. /EMERG (Enabling the Emergency Mode)
/EMERG enables the Emergency Mode for variant –(201) only.
RT6512-(201) detects a low state on the /EMERG input when an external resistance lower than 1 kΩ
connects to ground. In such case transceiver activates Emergency Mode operation.
RT6512-(201) is detecting high state on the /EMERG input when an external resistance higher
than 50 kΩ connects to ground.

General Description
Scope of Functionality
18 RT6512 DV17501.03 Issue 05 May 2017
1.5.6. Status and Control Outputs
1.5.6.1. /FAILURE
Figure 4 /FAILURE Output Schematic
This /FAILURE output is coupled to the status shown at the status LEDs mounted at the connector
side of RT6512. It corresponds to OR function of the red and the yellow LEDs. When the test function
is not ok, the transistor in the /FAILURE output is ON.
This output is an open collector (drain) type with capability to:
•Drawmaximum100mAcurrenttogroundwith a voltagedrop oflessthan2.5V
(correspondingLEDsis on),
•Drawmaximum0.1mAcurrenttogroundforoutputvoltage28.0Vwhenin"inactive" state
(correspondingLEDs areoff).
It can be used to drive an external relay if 100 mA output current limit at the supply voltage 28.0 V is
not sufficient. This /FAILURE output is protected against spikes produced from a relay. See "Status &
Error Indication", page 53.
1.5.6.2. RX_AGC (AGC Voltage of the RX-RF-AGC)
The AGC output is a DC coupled output of the RF-AGC used in the receiver.
The output voltage varies monotonic within the range of 0...5 V, when the input level at the antenna
input is varied from -105...+13 dBm.
For all antennas input levels from -120...-105 dBm the output voltage is positive and not higher than
the output voltage which can be obtained at -105 dBm.
1.5.6.3. /SQL_EVAL
This digital output indicates that the audio signal from the receiver is available on the LINE_OUT.
This output is an open collector type with capability to:
•Drawmaximum100mAcurrenttogroundwithavoltagedropoflessthan2.5V
(correspondingLED(s)ison).
•Drawmaximum0.1mAcurrenttogroundforoutputvoltage28.0Vwhenin"inactive" state
(correspondingLEDs areoff).
•It can be used to drive an external relay, if 100 mA output current limit at the supply
voltage 28.0 V is not sufficient.
•This /SQL_EVAL output is protected against spikes produced from a relay.
•RX indication inactive (HIGH):
oSquelch ON but no audio goes out on LINE_OUT.
oRT6512 in TX mode.
•RX indication active (LOW), only possible in RX mode:
oSquelch ON and audio goes out on LINE_OUT.
oSquelch OFF (permanent audio out on LINE_OUT).

General Description
Scope of Functionality
DV17501.03 Issue 05 May 2017 RT6512 19
1.5.7. Digital Interfaces to the Control Unit
1.5.7.1. Interface ARINC 429
Name
Function / Remarks
ARI429_RX_A1
1st ARINC 429 Interface RX Line A
ARI429_RX_B1
1st ARINC 429 Interface RX Line B
ARI429_TX_A1
1st ARINC 429 Interface TX Line A
ARI429_TX_B1
1st ARINC 429 Interface TX Line B
ARI429_RX_A2
2nd ARINC 429 Interface RX Line A
ARI429_RX_B2
2nd ARINC 429 Interface RX Line B
ARI429_TX_A2
2nd ARINC 429 Interface TX Line A
ARI429_TX_B2
2nd ARINC 429 Interface TX Line B
1.5.7.2. Interface RS422
Name
Function / Remarks
RS422_RX+
RS422 Interface RX Line B (high if idle)
RS422_RX-
RS422 Interface RX Line A (low if idle)
RS422_TX+
RS422 Interface TX Line B (high if idle)
RS422_TX-
RS422 Interface TX Line A (low if idle)

General Description
Safety-Conscious Utilization
20 RT6512 DV17501.03 Issue 05 May 2017
1.6. Safety-Conscious Utilization
For safe operation of the product, the following notes have to be observed:
•Only an authorized installation company may carry out the installation of the
device into an aircraft. The country regulations always have to be observed.
•Use the product only within the specified conditions, see "Technical Data",
page 21.
•Power supply:
oDo not connect the unit to AC sources.
oMake sure that the unit is connected to the mandatory DC source, see
"Technical Data", page 21.
oDo not connect the unit with reversed polarity to the DC source.
•Circuit breaker:
oUse the recommended fuses in the power supply line to protect the
application, see "Technical Data", page 21.
Excessive pulses on the DC bus of the aircraft may cause damage on electrical
circuits of any installed instrument.
Do not switch ON the device during engine start or shutdown.
1.7. Restriction for Use
The product is to be used inside the declared limits.