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Trutrak /GRT Horizon EX

rvator4twa

Well Known Member
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Procrastinating can be problematic but after 10 years I am trying to get my DII VS to follow a GPS course. I have upgraded my original Horizon WS to the EX with its 6 serial outputs and added a second screen, a Sport EX. Is it necessary to have an Arinc module or will the EFIS GPS be capable of providing the signal to Trutrak through one of the serial outputs?

Bendix/King has purchased Trutrak and offers little to no tech support and GRT now has their own autopilot available.

Thanks
 
I would ask what you are driving the TT with, the internal GPS or an external source?
I had an older model TT which I drove through a GRT Sport SX, no issues. I drove it with a Garmin 430. I did use an ARINC because I drove the TT from the 430.
I have since traded my older TT in for a newer TT and IFD440.
I believe the GRT EX will drive your TT, contact GRT support, they will help you, they helped me with connecting both TT A/P’s.
 
Since you didn't mention a "navigator", I presume you have a GPS with position data (only). You should be able to send this info to the autopilot with a single RS232 link. The TruTrak will then fly headings, or follow a gps course. It will not do turn anticipation ("GPSS"), nor will it fly a glide slope. Altitude changes will need to be entered directly on the TruTrak.
If you do have a "navigator" (G-430W, 540, IFD440, or other) you will need the ARINC lines to have glide slope and GPSS capability, along with controlling altitudes from the EFIS.
 
Trutrak

I would ask what you are driving the TT with, the internal GPS or an external source?
I had an older model TT which I drove through a GRT Sport SX, no issues. I drove it with a Garmin 430. I did use an ARINC because I drove the TT from the 430.
I have since traded my older TT in for a newer TT and IFD440.
I believe the GRT EX will drive your TT, contact GRT support, they will help you, they helped me with connecting both TT A/P’s.

Skid and Bob,
All I have is the internal gps with each EFIS. No 430. Would be happy just to track a course. Thanks for your responses and any others that may have similar equipment and if possible how you rigged the wires to achieve this. GRT has helped but there is differing opinions and I am not moxie enough to really help them.
Thanks
 
All you need to do is connect the serial output from the EFIS to autopilot. If I recall correctly, GRT simulates GPSS using the serial line. I'm not sure about the serial settings on the GRT, but on the TT all you need is to connect the serial and set the baud rate to match the output on the GRT (likely 9600).
 
Going from memory here…..I think the GRT will output NMEA or Aviation format (choose in serial port setup) at 4800 or 9600 baud rate (choose in serial port setup).
Edit: For the record, from my GRT Hx, I use format: Aviation, at 9600 baud, but I'm controlling a Trio Pro, the TT may have different needs.
 
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Always nice seeing Bob's helpful posts!

I have a similar setup, Sport 200SX to Trutrak 385, lateral serial only- holler if you need any set menu samples.
 
Skid and Bob,
All I have is the internal gps with each EFIS. No 430. Would be happy just to track a course. Thanks for your responses and any others that may have similar equipment and if possible how you rigged the wires to achieve this. GRT has helped but there is differing opinions and I am not moxie enough to really help them.
Thanks

As Andrew stated all you have to do is connect a serial out from the EFIS to the serial in on the A/P. I have attached a screen grab of the DII A/P install manual showing the pin to use, pin 17, the EX manual does not specify a serial port to use as they are apparently configured by the user. The baud rate is important, make sure they match on the EFIS and A/P, as Andrew stated use 9600.
 

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TruTrak

Thanks to everyone who responded, many more than once. I have often said that Marines like pictures, preferably in color. Will give this a shot tomorrow.
 
Trutrak

Traced the wires today and I had actually wired it properly but failed to follow through. The serial out port was off. A/P getting gps now. Didn’t get a chance to fly it yet. Now to see if I can learn to use it. Thanks for the help everyone.
 
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