I fix I'd like to see on the JPI EDM800

drgwentzel

drgwentzel

Pre-takeoff checklist
Joined
Sep 7, 2008
Messages
284
Location
NJ
Display Name
Display name:
Kobra
I have an EDM800 with the fuel computer option. I think there is a fix to the firmware that is sorely needed. Below is an email I sent to JPI. I wonder if others who own one of these units have a similar frustration. Let me know.

<snip>

To the EDM engineers and / or firmware developers:

I have a suggestion to the EDM (700-800) with the fuel flow option.

First, let me explain my situation:

• I own a Cessna Cardinal RG with two 25 gallon wing tanks. I have no auxiliary tanks.

• I own the plane with a partner who doesn’t utilize the EDM800. Therefore, I never know if the unit is in sync with the fuel state of the aircraft when I go flying. Soooo….

Let’s go over a typical scenario:

• I show up to fly
• My partner flew before me
• I have no idea if he added or removed fuel to or from the airplane
• I have no idea if he utilized the EDM800 to enter the proper fuel amount
• I perform a preflight, stick the tanks and determined that I have 36 gallons total fuel
• I start the engine and turn on the Avionics Master and the EDM800 boots up

Now here is what I am presented with by the EDM:

“FILL ?N”

It’s a nebulous question at best, because it’s not really asking me if I “FILLED” the tanks. If you think about it, it’s really asking me this question:

“When you shut me down last, I calculated that you had a certain about of fuel remaining in the tanks. Is the amount I calculated different in any way from what you know you have in the tanks right now?”

That is really the question it is asking. The problem is, that I cannot answer that question unless the EDM shares with me what its last calculated value was. The only thing I really know is that I have 36 gallons in the tanks.

I think the best question the EDM can initially ask is: “FUELxx?” Where “xx” is the number of gallons the EDM calculated remained in the aircraft the last time it was shut down. Let’s say when it boots up it says, “FUEL20?”

If I determined that I have 36 gallons, I now have all the information I need to tell the EDM that I did indeed “REFUEL” and that I need to ADD 16 gallons to the unit's total to bring it to the known fuel state of 36 gallons.

By telling the user immediately how much fuel the unit thinks it has, we can ADD or REMOVE fuel to correct the EDM’s calculation without going into a bunch of button gymnastics.

I hope all this rambling makes some sense, and I hope this can be added to a future firmware update.

Do you have any plans to update the firmware in these units? BTW, CAN the firmware be updated?

Gene Wentzel – CFI, CFII
 
Hmmm, IIRC the system works the same as my JPI, you answer yes to fill then it gives a full fuel option, you skip that and it gives you the ability to add specified gallons. Not sure though, it's been a long time since I used an EDM.
 
The interface is confusing, I'll grant you that. In fact, it's terrible. But, all the functionality I think you want is there.
qe7a9u4e.jpg
 
Not sure if a fix is needed since your case is probably in the minority, but the quick solution is to select NO, check the fuel remaining, and if wrong, hold LF and STEP together for 5 seconds and you're right back to the first display where you started, and can correct the fuel.

The problem with what you are doing is that sticking the tank is considerably less accurate than at least getting your inconsiderate partner to log his fuel added onto a sticky note so you can input the correct amount.

I doubt your sticks are accurate to a tenth of a gallon, nor is the ground always level where one might check the tanks.
 
ElPaso Pilot said:
Not sure if a fix is needed since your case is probably in the minority, but the quick solution is to select NO, check the fuel remaining, and if wrong, hold LF and STEP together for 5 seconds and you're right back to the first display where you started, and can correct the fuel.

The problem with what you are doing is that sticking the tank is considerably less accurate than at least getting your inconsiderate partner to log his fuel added onto a sticky note so you can input the correct amount.

I doubt your sticks are accurate to a tenth of a gallon, nor is the ground always level where one might check the tanks.
Click to expand...

bingo!
 
Henning said:
Hmmm, IIRC the system works the same as my JPI, you answer yes to fill then it gives a full fuel option, you skip that and it gives you the ability to add specified gallons. Not sure though, it's been a long time since I used an EDM.
Click to expand...

Yes...you are correct. The buttonology you state above would work IF you knew how much the EDM had calculated was on board. The problem is that I don't know how much fuel to add or subtract since the unit did not tell how much fuel it "thinks I have".

Try this analogy:

Your accountant calls you up and leaves a message on your voicemail, "Hey, John is the amount of money you have in your checking account right now the same amount that I saw when I looked into the account about 2 weeks ago? If it's not, please tell me how much I need to add or subtract from your register to balance the account. Just leave a message on my voicemail as I'll be away next week."

I think you would consider the account stupid, incompetent or inefficient for not sharing with you how much he saw in your account immediately. Now you have to waste time calling him back, leaving a message and asking him for the information he should have provided in the first call. :mad2:
 
Fire it up, decline everything, find what it thinks, if it's not what you measured, reboot and add what you need. For some reason avionics makers never heard the term "user friendly".
 
ElPaso Pilot said:
Not sure if a fix is needed since your case is probably in the minority, but the quick solution is to select NO, check the fuel remaining, and if wrong, hold LF and STEP together for 5 seconds and you're right back to the first display where you started, and can correct the fuel.
Click to expand...

You are correct. But you should understand that what you are describing is called a "workaround". A workaround is a "long-way-around" detour to navigate an ill-conceived algorithm and you utilize it while you await a more efficient solution.

An Algorithm that might work could look like this:

1: Question: Fuel30? Answer: Tap STEP for “Yes”, Exit
Answer: Tap LF for “No”, Go to line 2

2: Question: Full50? Answer: Tap STEP for “Yes”, Exit
Answer: Tap LF for “No”, Go to line 3

3: Press “LF” to ADD Fuel up from 30 and Tap “LF” to REMOVE Fuel from 30, Tap STEP when done, Exit
 
drgwentzel said:
I have an EDM800 with the fuel computer option. I think there is a fix to the firmware that is sorely needed. Below is an email I sent to JPI. I wonder if others who own one of these units have a similar frustration. Let me know.

<snip>

To the EDM engineers and / or firmware developers:

I have a suggestion to the EDM (700-800) with the fuel flow option.

First, let me explain my situation:

•I own a Cessna Cardinal RG with two 25 gallon wing tanks. I have no auxiliary tanks.

•I own the plane with a partner who doesn’t utilize the EDM800. Therefore, I never know if the unit is in sync with the fuel state of the aircraft when I go flying. Soooo….

Let’s go over a typical scenario:

•I show up to fly
•My partner flew before me
•I have no idea if he added or removed fuel to or from the airplane
•I have no idea if he utilized the EDM800 to enter the proper fuel amount
•I perform a preflight, stick the tanks and determined that I have 36 gallons total fuel
•I start the engine and turn on the Avionics Master and the EDM800 boots up

Now here is what I am presented with by the EDM:

“FILL ?N”

It’s a nebulous question at best, because it’s not really asking me if I “FILLED” the tanks. If you think about it, it’s really asking me this question:

“When you shut me down last, I calculated that you had a certain about of fuel remaining in the tanks. Is the amount I calculated different in any way from what you know you have in the tanks right now?”

That is really the question it is asking. The problem is, that I cannot answer that question unless the EDM shares with me what its last calculated value was. The only thing I really know is that I have 36 gallons in the tanks.

I think the best question the EDM can initially ask is: “FUELxx?” Where “xx” is the number of gallons the EDM calculated remained in the aircraft the last time it was shut down. Let’s say when it boots up it says, “FUEL20?”

If I determined that I have 36 gallons, I now have all the information I need to tell the EDM that I did indeed “REFUEL” and that I need to ADD 16 gallons to the unit's total to bring it to the known fuel state of 36 gallons.

By telling the user immediately how much fuel the unit thinks it has, we can ADD or REMOVE fuel to correct the EDM’s calculation without going into a bunch of button gymnastics.

I hope all this rambling makes some sense, and I hope this can be added to a future firmware update.

Do you have any plans to update the firmware in these units? BTW, CAN the firmware be updated?

Gene Wentzel – CFI, CFII
Click to expand...

Agree. The user interface is not great. I would also prefer if the first question is fuelxx.


Sent from my iPad using Tapatalk HD
 
I hear you loud and clear on your suggestion, and I can't deny the usefulness or validity of it but the absolute easiest solution is to get your partner onboard and savvy with the equipment in your airplane. We're monitoring an air cooled four banger, this isn't rocket appliances.
 
You must log in or register to reply here.
Back
Top