EDM data issues, again.

[Bob_Belville]

So I Got a new spring for the oil pressure relief valve, one size up. Moved the OP up a little which is a good thing.

 

But while making several test flights to tune the valve in I find 3 bothersome parameters. See pic of graphs.

 

• Tach is erratic. (This is a nearly new prop and governor.)
• Oil Pressure used to be flat line in cruise.
• But the biggest concern is Fuel Flow. There is little reason to believe the level which is higher that the system is capable of. (EGTs, engine performance indicates there' nothing amiss.

 

I just cleaned ground connections and electrical connections forward of the firewall.

 

Sent JPI a note but wonder if someone here has been there with this one? 

SavvyAnalysis - N943RW 2015-08-31 19 51.html

[N601RX]

One thing I have noticed about JPI's file formatt is that some of the parameters are rounded up and down when saved. I think oil pressure was only logged in 6psi increments. For example if it is logging back and fourth between 70 and 76 it may only be changing from 73 to 74 and rounding makes it look worse. Look at the raw numbers and see if they jump by 6 most of the time.

[Bob_Belville]

One thing I have noticed about JPI's file formatt is that some of the parameters are rounded up and down when saved. I think oil pressure was only logged in 6psi increments. For example if it is logging back and fourth between 70 and 76 it may only be changing from 73 to 74 and rounding makes it look worse. Look at the raw numbers and see if they jump by 6 most of the time.

What gets save is the jumpy data points. I had the EDM set up for 2 sec intervals instead of the default 6 sec. But OPress in data file shows jumps from 62 to 56 (for 2 readings) and back to 62. Actually, I think the display hits intermediate values. I may have to make a video though to document. 

[Marauder]

What gets save is the jumpy data points. I had the EDM set up for 2 sec intervals instead of the default 6 sec. But OPress in data file shows jumps from 62 to 56 (for 2 readings) and back to 62. Actually, I think the display hits intermediate values. I may have to make a video though to document.

I think that is his point. Even though you are saving it at 2 second intervals, what gets saved is the rounded up or down version. 2 seconds is an eternity in electronics. I have mine saved 1/sec. Now you both got me wanting to look at my data closer.

Sent from my iPad using Tapatalk

[N601RX]

The display shows 1psi increments, but they use an data compression algorithm that rounds up or down to save memory in the saved data.  I guess this is a holdover from older products as flash memory is now large and cheap.

 

Actually the compression algorithm they use saves the starting psi and them only makes an entry when the PSI changes by a rounded increment of 6 psi or more.

[Bob_Belville]

The display shows 1psi increments, but they use an data compression algorithm that rounds up or down to save memory in the saved data.  I guess this is a holdover from older products as flash memory is now large and cheap.

 

Actually the compression algorithm they use saves the starting psi and them only makes an entry when the PSI changes by a rounded increment of 6 psi or more.

ISTM that basically sucks. Any chance JPI has or will do something different? My 930 is almost 4 years old but I sent in back to the factory a year ago (chasing MAP fluctuations) at which time the software was updated.

[Marauder]

ISTM that basically sucks. Any chance JPI has or will do something different? My 930 is almost 4 years old but I sent in back to the factory a year ago (chasing MAP fluctuations) at which time the software was updated.

I suspect the key concerns during certification was what was displayed to the pilot and what triggered the warning annunciations. The data recording was probably an afterthought and was handled as N601RX indicated because of the original memory limitations.

BTW -- pursuing this change with JPI sounds like a good activity for a retired guy. Know any?

Sent from my iPad using Tapatalk

[N601RX]

I noticed this a few years ago and ask their tech support about it.  I was told that's just the way it works.  If you look at their other saved data you will notice that is all rounded in some manner. The good side to this is that we can store something like 50 hrs of flight data.  My brother put a Dynon in his RV and it will only hold 30 minutes of data but.

[Bob_Belville]

I suspect the key concerns during certification was what was displayed to the pilot and what triggered the warning annunciations. The data recording was probably an afterthought and was handled as N601RX indicated because of the original memory limitations.

BTW -- pursuing this change with JPI sounds like a good activity for a retired guy. Know any?

Sent from my iPad using Tapatalk

You can be sure this retired guy, who has honey to take off, wine to rack and bottle, a fall garden to prep and plant, several house repairs to get done... will be talking to JPI as soon as the left coast wakes up. (Julie Stanczyk, who was helpful a year ago may not be there, her email account got an auto reply that that address was no longer monitored. I think her husband works in the tech service area.)

 

Has anyone here had recent contact with the factory/tech service? 

 

And I will be very interested in any advice on the false readings on fuel flow. This is pretty critical. The "used" and "fuel remaining" info is following the faulty flow reading. 

[Marauder]

You can be sure this retired guy, who has honey to take off, wine to rack and bottle, a fall garden to prep and plant, several house repairs to get done... will be talking to JPI as soon as the left coast wakes up. (Julie Stanczyk, who was helpful a year ago may not be there, her email account got an auto reply that that address was no longer monitored. I think her husband works in the tech service area.)

Has anyone here had recent contact with the factory/tech service?

And I will be very interested in any advice on the false readings on fuel flow. This is pretty critical. The "used" and "fuel remaining" info is following the faulty flow reading.

Bob -- I do all that and work a 10 to 12 hour day! Wimp!

The guy in tech support who I worked with when my JPI was interfering with my Garmin GTN was named Tim. Sorry, I don't have his last name.

Sent from my iPad using Tapatalk

[Bob_Belville]

Bob -- I do all that and work a 10 to 12 hour day! Wimp! 

 

B26, yeah, when I was your age there were more hours in a day. And of course back then I used to sleep every other night. But most importantly, there was no MooneySpace requiring my attention. 

[N601RX]

There was some recent post on Beechtalk that JPI had very recently changed their software for the 900/930. The new software removes the numerical value from the fuel tank displays and just shows Full and Empty depicted by a yellow/green slider.  They were updating the software on any any unit returned for repair, and it wasn't being received very well.

[Marauder]

There was some recent post on Beechtalk that JPI had very recently changed their software for the 900/930. The new software removes the numerical value from the fuel tank displays and just shows Full and Empty depicted by a yellow/green slider. They were updating the software on any any unit returned for repair, and it wasn't being received very well.

I was one of the guys they made the change to:

Before:

After:

I like the new colors and quite honestly, rarely look at the tank levels since I monitor the fuel used pretty religiously.

Sent from my iPad using Tapatalk

[kortopates]

Since you still have fuel remaining (from both tanks together) I am not sure that's such a bad thing. If you look at downloaded data for Left and Right fuel levels you'll see it osicllates up and down quite a bit from the fuel moving around in flight anyway.

[Bob_Belville]

I talked to Tim at JPI at 8:30 this morning (CA time) he was already working on the email I sent him late last night. Hopefully he'd get with the real nerds and have some info for me soon.

 

Chris, did you have to return your unit to JPI? Has anyone been able to do firmware/software updates in the field?

[Marauder]

I talked to Tim at JPI at 8:30 this morning (CA time) he was already working on the email I sent him late last night. Hopefully he'd get with the real nerds and have some info for me soon.

Chris, did you have to return your unit to JPI? Has anyone been able to do firmware/software updates in the field?

Sorry Bob I didn't respond earlier. This pesky job kept me busy.... What did you do today?

I did return my unit. I returned it to fix the fluctuating MP pressure (which BTW is still fluctuating a little). When I got it back, they had reprogrammed it with new firmware for the MP issue and to reset my tach time. When I got it back, that is when I saw the display had changed as well.

Sent from my iPad using Tapatalk

[N601RX]

They emailed me field update of the software and config file last fall.  It only took a couple of minutes to install

[Bob_Belville]

They emailed me field update of the software and config file last fall.  It only took a couple of minutes to install

Thanks! That's what I wanted to hear. Hopefully we won't have to remove the unit and ship it to CA like we did a year ago.