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mapMX Question


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I have a GTN650 and GDL-39 that previously were hard wired to a GPS695. The 695 stopped showing approaches reliably so I've decided to replace it with the aera 760. The instructions for the bare wire installation are not completely clear.

1. With the GPS695 I used "Aviation In" from my GTN (and 300XL). The aera recommends mapMX. Will I be able to use the same connection from the GTN that I previously used? Do I need to reconfigure the GTN to send mapMX data?

2. The GPS695 used a pass through feature where data from the GTN first went to the GDL and then to the 695. I'm pretty sure this doesn't work on the aera. I believe I should use serial 1 for the GDL and serial 2 for the mapMX. Is that correct?

Thanks in advance!

By the way, while I'm here I think the documentation that comes with the aera 760 leaves a lot to be desired. There is no printed user manual, only a 200+ page pdf. How are you supposed to use that in flight? Also my GPSmap695 had a nice press on cover that was great when leaving the unit in the plane. The aera has nothing similar that I'm aware of.

Peter

N201CM

Australia

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Hi Don, Sure I can do that, but I really prefer the actual manual. The aera actually has the user manual in pdf form on the device, but navigating to a particular page seems quite difficult.

Anyway...

I did my best with the bare wire kit. The GDL works fine on serial port 1. I selected "aviation in" on serial port 2 and it shows connected to my GTN... However, no flight plan is displayed on the aera 760 and I get a message "Route Memory Full."  I have no clue what to do about this. The unit is brand new and has no stored plans or routes. The GPS is working and shows correct position and waypoints. I tried mapMX but it will not connect to the GTN. Either a setting is wrong in the GTN for this format or the pin out is incorrect on the GTN (or both). Anyone know what I need to do?

Thanks!

Edited by Peter Rejto
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Mapmx is only available on one serial port at a time..  if you have two devices needing mapmax from the gtn, you have to splice the one serial out connection from the gtn to go to both units.  

You can use your existing serial port connection and reconfigure the output on the gtn to mapmx and the input on the aera to mapmx.   If gtn output is still set to aviation out, then it won’t work on the aera.   It sounds like this might be what you are experiencing.  You setup output protocols on the gtn by holding the home button while powering up.  You have to select save settings before shutting down.  

Edited by Browncbr1
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Hello Browncbr1,

Thanks so much for the information! Just to clarify, are you saying that Aviation out from the GTN will not work even if Aviation In is selected on the aera? or are you saying that if Aviation Out is set on the GTN then selecting mapMX on the aera will not work (which I have confirmed to be true).

At the moment I have the wire from the GTN connected to the purple serial #2. I don't believe I am required to connect the orange TX2, correct? The aera indicates connected.

I will try configuring the GTN to output mapMX.

Thanks!

Aera Wiring.pdf

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Some progress!

I switched the GTN to mapMX and set the aera to mapMX and all seems good! It sure would be nice if Garmin clarified the user manual on this point! The manual states only that mapMX is preferred. It certainly doesn't say that aviation out will not work. I find this rather strange given that the aera has a setting for aviation in. Is the implication that it will only work with Garmin navigators that only have aviation out? I tried Aviation out from my Garmin 300XL; it also would not work with the aera but works fine with my GPSmap695. I don't think the 300XL can output mapMX.

Of coarse I solved one problem only to create another. It seems the serial port on the GTN is shared with my Shadin mini-flo. Now the mini flow won't operate with the mapMX setting. I guess I will be paying some big dollars to an avionics shop to fix this up.

Thanks all for your help.

Peter

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I was trying do something similar with my aera 560 to provide my GNC-255 Nav/Com geographic position for frequency tuning. So the 255 would display the frequency 119.9 is  KSEA TWR.  I wasn't successful on getting the aera portable to do that.  Garmin said could be done.  I was comparing the output between GNC-355 GPS/Com RS232 tx output and the aera 560 RS232 serial tx output. I noticed that aera 560 TX output levels were low -2.5 v if recall correctly. Were the output for RS232 TX signal I believe should be -5v level at least that I I recall seeing from GNC-355.  I suspect the rs232 output level from the gps portables are too low to drive certain devices without some sort of booster/converter. The weird thing about it is that the Area was able to drive my EI CGR30P engine monitor for lat/ long position but unable to provide gps position for the Nav/Com made by the same manufacturer. This just a hunch on my part. I am not an engineer.

James '67C

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I had the same issue where I was originally using Aviation Out from the GTN-650 to the AERA-660.  When the 660 stated to support MapMX, I wanted it switched.  It was just under an hour of time for the shop to make the switch, not too expensive, and well worth it.

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Thanks all for the replies!

I've sent a message to Trek and hopefully he might provide input.

I can understand that mapMX is the desired format. What I don't understand is why aviation out from the GTN will not work at all and why it throws the  "route memory full" error. It would be nice to be able to operate both pieces of equipment (Shadin + aera760) until I can get to a shop. Where I live in Australia this is a 1 hour flight each way + landing fee at Bankstown and I guarantee this will be more than 1 hour of labor! A pity because it wasn't 3 weeks ago that I did the same for my FAR43 checks.

Edited by Peter Rejto
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Is mapMX a Garmin  format ? or universal  GPS format?

I have noticed that some of Garmin's terminology isn't always  the way I have learned it or understood it. For example on my Aera  560 it's RS232 I believe in it's 'Aviation in' it has 2 options "Fast" and "Normal". If you are like me you would think that the term 'Fast ' would have something to do with baud rate but it did not. It appears to difference between "Fast" and "Normal" is add/subtracting the number of GPS Labels is being sent from the GPS unit.   I was using a laptop with PUTTY application looking at the  GPS strings/labels coming into serial port. I would have expected that  when I went to "Fast" mode  on the GPS would had changed the baud rate and I would seen garbage on the screen on my laptop but I did not they were readable labels.

I discovered on my GNC-355 (GPS/COM) which has 3 RS232 ports you only have one format per port and no duplicates. In other words on my RS232  #1 port is  MapMX  format RS232 Port#2 & RS232 Port#3 can not be set to MAPMX format since it already used by serial port#1. Likewise with RS232 Port#2 & Port#3 they have to be different formats for each port.

In my case I have my RS232 Port#1 driving my two G5's with a GAD29B for the ARINC429 to CAN. So I am able to toggle the CDI  display on the G5's between GNC-255 (Nav/COM)  for the ILS , VOR/LOC and CDI of the GPS from the GNC-355(GPS/COM).

It's weird  because I have my RS232 port#3 (GNC355)  configured as "Aviation output2" connected to  GNC255 set to Avn IN/MapCOM  to Give  COM radio frequencies geographical referencing. I have daisy chained RS232 port#3 (GNC-355) to  E.I. CGR30P   engine monitor so I can get LAT/LONG data and the GNC-255. But when I look at  the way point field on CGR30P CSV file.  All the way points come across fine. The airports show up as Altitude or Garmin or ??? in the way point field. The LAT/LONG fields look fine.

Not sure if that is the case on the GTN and GNS series or if this is some sort of FAA mandate.

James '67C
 

 

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My understanding about why mapmx format is only available on one port has to do with hardware limitations.   I have my gtn mapmx output port spliced to G5s and Aera660.   Arinc goes to the gad29b

i would rather do it that way rather than in series as the OP described because it’s easier and keeps the aera dependent on just the gtn rather than the gtn AND other boxes.  

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