Trig Avionics Mode-S User manual

Mode-S transponder
2020 compliance
installation and options
for MGL EFIS systems

General
This document describes installation requirements for 2020 compliance with ADS-B extended
squitter transmissions using a Trig Avionics mode-s transponder
This document assumes the following minimum firmware versions:
iEFIS G3: 1 0 4 4
Trig transponder interface: 110119 (11 January 2019)
SP-12: 100119 (10 January 2019)
How to check versions:
Assuming devices installed Use the EFIS Diagnostics menu and select “Mode-S installation
checks” If this item does not exist, update your EFIS firmware to the latest release available
from the MGL Avionics website
Using this diagnostics function it will show you the Firmware versions installed in the Trig
interface and SP-12 If any one of these does not meet the minimum version number it will
show you “outdated” In this case you can update the relevant device via the EFIS using
firmware files you can download from the MGL Website- instructions are provided on the
website
Compliance options
You connect your Trig transponder via the MGL Trig interface to an MGL iEFIS The Trig
interface is connected to your EFIS via CAN bus
You have two options:
1) You have the EFIS and the Trig transponder Ensure both have firmware updated to at
least the firmware levels mentioned in this document
In this case your ADS-B transmissions are compliant to SIL/SDA of 1/1 and TABS
TSO-C199 for a Class-B device This does not meet 14 CFR §91 227c, AC 20-165B,
Appendix B requirements The GPS may be used in all conditions not excluded by
these documents
This setup is compliant to the requirements outlined in TSO-C199 A 1 2 5 6 and
following paragraphs
NIC is set to 0 5NM (6), SDA=1, SIL=1, HFOM and VFOM are set according to the
formulas given in the document derived from HDOP and VDOP with UERE of 6
meters NACv is set to 1 (10m/s)
The Navigation source (GPS in the EFIS) is a class Beta device to RTCA/DO-229D
implementing the en-route case The GPS is a WAAS GPS and implements RAIM with
multiple satellite exclusion capability on pseudo range errors The GPS will continue to
provide position data with excluded satellites

2) You have the EFIS and the Trig transponder In addition you have the SP-12 TABS
GPS module connected to the SAME CAN bus as the Trig transponder interface
Ensure all three devices have firmware updated to at least the firmware levels
mentioned in this document
In this case your ADS-B transmissions are compliant to SIL/SDA of 3/2 and TABS
TSO-C199 for a Class-B device This DOES meet 14 CFR §91 227c, AC 20-165B,
Appendix B requirements
In this case all ADS-B related transmission data items are set as required in DO-260B
based on the data sent by the SP-12 GPS to the Trig interface In this case the data is
NO routed via the EFIS and the link remains operational even with the EFIS switched
off
Note: In this case the GPS in the EFIS is still being received by the Trig interface as
well The Trig interface SHALL use the position and accuracy data from the SP-12 if it
has a valid fix The Trig interface SHALL default to the position and accuracy data from
the EFIS as backup should the position from the SP-12 not be valid In this case the
provisions of section 1) above applies
Other documents to reference
Please view the documents titled:
SP-12 pdf – User and installation manual for SP-12 GPS module
MGL Avionics Trig Transponder interface pdf
Both documents are available for download from the MGL Website

Configuring the EFIS for a mode-s transponder
You need to configure the use and parameters needed for your Trig transponder installation in
your EFIS This is quite simple to do You will find the setup for this in the System Setup Menu
under “Transponder setup menu”

Type
Select: Mode-S on CAN
Aircraft callsign
Enter your aircraft's identification This information will be broadcast by your transponder
ICAO ID
Enter the ICAO ID that has been obtained from you by your aviation authority This is a unique
number that will identify your aircraft and country of origin This information is broadcast by
your transponder and is a vital part of a mode-s interrogation
Note that the number is entered in OCTAL notation Should you have been given a number in
decimal or hexadecimal – there are many freely available online converters that will convert
your number to octal
VFR Sqauwk code
Enter the code used in your area as VFR code This information is used by your EFIS only It
is used for a “one button” selection of the code
Aircraft speed
Select the speed range applicable for your aircraft This information is broadcast by your
transponder
Category
Select the aircraft category applicable to your aircraft This information is broadcast by your
transponder
Lengt and Widt of aircraft in meters
Enter the relevant dimensions of your aircraft This information is broadcast by your
transponder
UAT ADS-B and 1090ES receiver installed
Select the appropriate setting for your aircraft This information is broadcast by your
transponder
Slave ADS-B ↔ Transponder
If you have a compatible ADS-B transceiver connected you can use this setting to slave the
two devices In this case both will transmit the same squawk codes and you do not have to
separately enter them

Squat switc is...
Select how you would like to handle the “on-ground” detect The transponder will transmit in
ground or airborne mode Make sure it will transmit airborne mode when you are flying or else
you will have an unhappy ATC
In the Equipment enables menu, please check the box for the transponder This will enable
the EFIS to control your transponder and also enable the transponder user interface
ransponder operational interface and status
On all normal EFIS screens that have a transponder component you will see a small status
display as above You see the current squawk code, transponder operating mode - in this
case “ALT” which means it is active and will transmit altitude information (mode-c)
The transponder is in ground mode “G”
The transponder is using a certified GPS source “C” In this case it would be the SP-12
Alternatively it will show “E” for EFIS
The first “RF” is for the EFIS It means the transponder interface is receiving GPS information
from the EFIS and this GPS has a valid FIX
The second “RF” is for the certified source (SP-12) It means the transponder interface is
receiving GPS information from the SP-12 and this GPS has a valid FIX
Any item not available will be shown with a dash “-”

Tapping on the transponder status display opens the transponder control shown above
If you have an EFIS will buttons under the display you will notice that the buttons can also be
used instead of the touch screen
Note: If you enter a sqauwk code the code display turns yellow until you have entered all four
digits

Using the mode-s diagnostic function
Under the EFIS Diagnostics menu find and select “Mode-S installation checks” You will get a
display similar to:
The first section is dedicated to the SP-12 GPS (if available) It shows you the version number
of the installed firmware, GPS FIX status, number of satellites in view and how many are
tracked
Note that you can get more detailed information using the GPS status and selecting “CAN” as
GPS source The GPS status is available by tapping on the GPS information display on any
EFIS screen where this has been included as component Here you can find out information
such as signal strength for the various satellites, location in orbit relative to your position and
a lot of other detail
The second section is dedicated to your Trig transponder interface,
You can verify the installed firmware version and get an overview of the selection and status
of connected GPS sources