GRT Avionics and The Rotax 912is

[D&CJohnson]

[QUOTE=Eric Page;113293]I think what they're telling you is that the EIS cannot receive CAN data, so it won't work with the 912iS unless all of the sensors are duplicated. Their CANBUS adapter can receive Rotax CAN data, but it won't send it to an EIS, only to one of their EFIS screens (with the proviso that there may be some data that doesn't come from the ECU via CAN).

Thanks for your take on this Eric. I will definitely be making a phone call before ordering and I may go talk to them in person if they attend Oshkosh. Im a little more optimistic than I was reading the posted reply the first time. I guess it wouldnt be a big deal to use a different engine monitor, but I was hoping to use the EFIS as a stand-alone panel.

[Delta Whisky]

I'd give them a call. They are really helpful, easy to talk to and a no pressure operation. You'll most likely have more questions for them at OSH but they'll be refinement questions.

[ADK-Flyer]

I think what they're telling you is that the EIS cannot receive CAN data, so it won't work with the 912iS unless all of the sensors are duplicated. Their CANBUS adapter can receive Rotax CAN data, but it won't send it to an EIS, only to one of their EFIS screens (with the proviso that there may be some data that doesn't come from the ECU via CAN).

According to this page on the Dynon website, "Engine parameters available from the [912iS] engine computer include RPM, manifold pressure, oil pressure, oil temperature, coolant temperature, EGT for all four cylinders, ECU voltage, and engine hours." For further confirmation, look in the Dynon SkyView installation manual (first item under the Installation Guides tab). At the bottom of page 7-7 there's a table that shows which parameters are reported by the ECU and which require separate sensors.

Two notes:

• For fuel flow, you'll need a sensor in the supply line to the engine and another in the return line; the EFIS will have to subtract the return fuel from the supply. There should be an offset value in the settings that you can adjust to zero in on a dead-nuts accurate flow measurement.
• The ECU doesn't report CHT since the heads are water cooled. Instead it reports a single coolant temp value.

I remember reading somewhere (probably on the Rotax-Owner forum) that Rotax only releases their CAN protocol information to avionics manufacturers under an NDA, so the avionics companies seem to be the only source of info about what exactly the Rotax ECU sends out over CAN.

Lot's of good info here thanks. I ended contacting MGL avionics as well and apparently they have a similar adapter which works in a similar way. They had a lot of good info and I liked their systems but while using the system builder it seems almost everything I'd need is out of stock or backordered. After reading what they said it started to make more sense and you've cleared it up even more. So many options to choose from it makes it really hard to decide. I'd love to go Dynon or Garmin but the prices seem to be quite a bit higher.

[Redline]

I don't have experience with GRT but have heard great things. If you end up considering Dynon, I highly recommend them. We went with Dynon and the Advanced Flight Systems ACM, which is similar to the VP-X. Also had Advanced make up about 80 percent of the harnesses we needed and that saves a tremendous amount of time.

Dynon is one of the most responsive, customer-friendly companies I've ever dealt with. Super happy with the system and their tech support.

[jiott]

I second the comment about the Dynon Skyview. I went with the Skyview without the ACM or the premade harnesses, but still found the installation to be very easy and troublefree. I have no problem with those who choose the Garmin G3X, but it seems to me the majority of folks who report on this forum about their G3X installation have many issues and support phone calls before they are done. My need for support (beyond reading the Dynon installation manual) was nearly nil, and I am no electrical guru or engineer by any means.

[D&CJohnson]

GRT is pretty busy with Sun N Fun but I have traded a couple emails with a tech there regarding The CANBUS adapter and other functionality I had questions about. I will paste some of those replies below. I am going to be going forward with this. I am not wiring or installing anything just yet though so it might be a few months before I can report progress.

The CAN bus module should be $300 or around there. It connects to a serial port on the EFIS. It works with the two CAN bus monitoring lanes on the 912iS. Our module has a single bus so the lanes have to be connected together.

Our CAN bus module (adapter) document is linked from our Miscellaneous Documentation page:
https://grtavionics.com/media/CAN-Bus-Adapter.pdf

CAN connections have an H and L or High and Low wires/pins that work together as a pair. To connect to the module, you're supposed to connect the lanes wires together (H to H and L to L) and then use short wires from those to the module. This is shown in the attached diagram (they don't show the separate H and L wires). You would not connect the 120 ohm jumper on the module because the two lanes of the ECU have that.

[ADK-Flyer]

GRT is pretty busy with Sun N Fun but I have traded a couple emails with a tech there regarding The CANBUS adapter and other functionality I had questions about. I will paste some of those replies below. I am going to be going forward with this. I am not wiring or installing anything just yet though so it might be a few months before I can report progress.

The CAN bus module should be $300 or around there. It connects to a serial port on the EFIS. It works with the two CAN bus monitoring lanes on the 912iS. Our module has a single bus so the lanes have to be connected together.

Our CAN bus module (adapter) document is linked from our Miscellaneous Documentation page:
https://grtavionics.com/media/CAN-Bus-Adapter.pdf

CAN connections have an H and L or High and Low wires/pins that work together as a pair. To connect to the module, you're supposed to connect the lanes wires together (H to H and L to L) and then use short wires from those to the module. This is shown in the attached diagram (they don't show the separate H and L wires). You would not connect the 120 ohm jumper on the module because the two lanes of the ECU have that.

Did they happen to tell you what engine information is displayed on their EFIS panel when connected to the 912is with their module? I did a rough estimate on a Garmin G3X system with accessories and 2 axis AP and it was north of $17,000 pre tax. I would love to find something that integrates well with the 912is and I don't have to sell my first born to have. LOL

[Eric Page]

I did a rough estimate on a Garmin G3X system with accessories and 2 axis AP and it was north of $17,000 pre tax. I would love to find something that integrates well with the 912is and I don't have to sell my first born to have.

I don't know what your Garmin bill of materials includes but when I priced avionics, Dynon was significantly cheaper for a functionally equivalent system. The drawback is that Dynon's database updates are only available as a VFR/IFR bundle for $120/yr, vs Garmin's "VFR Plus" package for $50/yr (if you want VFR/IFR from Garmin, it's $225/yr). I figured I could buy many, many years of database updates for the difference in panel price.

That said, MGL is another step down in cost and gives up almost nothing compared to the other two. @alexM put together a nice MGL panel with two of their MX1 screens for quite a bit less than what I spent.

[D&CJohnson]

Did they happen to tell you what engine information is displayed on their EFIS panel when connected to the 912is with their module? I did a rough estimate on a Garmin G3X system with accessories and 2 axis AP and it was north of $17,000 pre tax. I would love to find something that integrates well with the 912is and I don't have to sell my first born to have. LOL

I did not directly ask GRT. I think the info Eric posted earlier was pretty solid. Apparently the Rotax ECM provides RPM, manifold pressure, oil temp, oil pressure, coolant temp, EGTs, ECU voltage and engine hours.

What I get from GRT in general is the efis will display the info it is given. For example, the TailbeaconX does interface with the Horizon 10.1 but the tail beacon doesnt send time/date to the EFIS so a rudimentary gps input would still be required. I had hoped the TailbeaconX would eliminate the gps source and its antenna.

GRT doesnt sell a rudimentary GPS so I will have to do some homework or just be lazy and plug in their $550 safe fly unit which apparently plugs right in.

DISCLAIMER here gents. I am not in any way a tech whiz. I should have a sign that says Do Not Follow closely. However, Ive asked questions and feel like I am satisfied with the level of risk to start buying. If you arent in a hurry get 🍿 and wait. I will certainly post the issues that arise.