Making sense of the MAP and TACH/RPM Ranges

[Tsperling]

I am new to Dynon. But, trying to understand how the system figures out the ranges (and names) for both the MAP and TACH/RPM sensors. When I view the User_Config file, and look within the "ems1 ={", the definitions for MAP and TACH/RPM are confusing:

1) With respect to the MAP definition (and I assume that widget is defined by c37_p26), it just has a single valid range between 0 and 17.1884. Why? And, yet, when I look at the widget in the 100% screen, it shows a much larger range that appears to be between approx 0-30. Why is that? Does the MAP widget pull its range from some other location within the code (not from the MAP definition)?

2) With respect to the TACH, I am confused too by what I see in the User_Config file. First, there appears to be two "valid" definitions that may apply. The first is "c37_p32/34_v2", and the second appears to be "c37_33/35_v2." Does that make sense--to have two valid definitions devoted to RPM/Tach? Second, both of those definitions list names ("RPM L," and "TACH R," respectively) that are different than the name within the EMS 100% screen, which is just "TACH"). Further, the ranges for those definitions do not appear in the widget for the 100% screen. The widget only shows a single green band, not multicolored as the ranges of these sensors imply. What gives? Am I wrong to think that the Widget in the 100% screen is dictated by one of these two definitions?

I have attached the User_Config file and screenshot of the EMS 100% screen.

Lastly, what are the "can_XXXX" definitions within the User_Config file? Are those just ignored by the system and placed in there to help with manual edits to the User_Config file?

Thank you in advance.

 

[Stevec]

I have to ask . Why if you are new to Dynon are you trying to decode the config files. If you work through the EMS setup menu you should be able to achieve everything you need to do setting up screen layout and widget parameters.

 

[Rhino]

I'm no expert at this, but I did stay at a Holiday Inn Express once.

C37 is the 37 pin connector, and 'p' is the pin numbers on that connector. The configuration setting numbers in the file don't indicate the actual measurement of pressure or RPM at the engine. They're used to control how the inputs on those pins are depicted on the video display. How the system interprets the measurement units from your engine sensors is native in the system, and not part of this configuration file.

The IDs are for reference only. It doesn't really matter what they say, as long as they identify what they are.

I think you may have misconfigured something. The top and bottom values for RPM L and TACH R are reversed. I assume you have a single engine, and are using pins 32-34. But most of the bottom numbers in your RPM L are higher than the top numbers, which might explain why your color bars aren't showing. I'd say you misconfigured something during setup, or you tinkered with the file and messed it up. You should go through the setup again. Or, if you changed the file and want to continue with file manipulation, I suggest backing this one up somewhere, pasting the range numbers from TACH R into RPM L, and see if that fixes your color bar issue. Since you're new to the system, I suggest choosing to go through setup again, like Stevec said.

Similarly, your MAP sensor is set to a max of 17.1884, but your reading is higher that that. Obviously it isn't configured correctly either. And since only range 1 is set as valid, you never get any color bars, assuming you want them.

You don't have an active TACH widget (without a letter) in your configuration file. The only entry for that is can_rpm, but that's set to valid=0, so it isn't active, and does nothing. I believe the can entries are for the Rotax CANbus anyway, and you apparently don't have a Rotax.

 

[Tsperling]

Thank you very much Rhino—your response is thoughtful and helpful. Know, I did not configure these settings. I recently purchased the plane, and the user_config file is as the plane was delivered. Just trying to make sense of what is there, before making changes. Unfortunately, I cannot ask the prior owner, as he is no longer with us.

Regarding the order of the defined colors in the ranges, I don’t think that matters (from what I have read).

The only explanation I can come up with for the disparity between the config file and what is being shown in the ems, is that the system is somehow ignoring the “RPM L” and “TACH R” definitions in the config file (even tho they are marked “valid”) because, perhaps, the pins for those sensors have been appended with “_v2”. My guess, and it’s only a guess, is that by making that change, the definitions are essentially unrecognizable to the software (and so essentially deemed “invalid”). And once deemed invalid, the system instead uses a default “tach/rpm” definition that is defined somewhere else in the system.

I will continue to investigate and will report back as I learn more. Again, appreciate your attention and thoughts on this.

 

[Rhino]

Did you by any chance update the system software recently? Versions before 16.2 displayed twin engines differently. Since you have both inputs set to valid, maybe a software update changed the way the config file is used by the system. I wouldn't think the valid setting on TACH R would do anything if there's nothing connected to pins 33/35. I would try setting it to valid=0. Going through SETUP MENU > EMS SETUP again should fix that too though.

 

[Rhino]

Okay, maybe I'm wrong. Looking at a 6 cylinder configuration file from a couple of years ago, and p32/34 is identical to yours. Hmmmm.