+1, yes, the UI is horrible even on JPI EDM730. It takes several years of getting use to it to be able to refuel correctly or even do something so complicated like a partial refuel where you ad fuel by repeatedly pressing a button and remove fuel by holding the same button. Or is it vice versa???
This is why I am keeping the separate Shadin Microflo fuel totaliser. That has a decent UI. The EDM700s and similar models with the fuel flow option were always horrible.
Have failed every time at correctly entering a refuel on the EDM700…Have a miniflo as well but haven’t tried it yet.
If you have two instruments working off the same fuel flow transducer, that is probably a duff installation… not the first time that’s been done. A failure of either one will bring down both (generally).
Interesting. The seller said to trust the EDM over the miniflo, which typically reads 1-2 L/hr different to the the EDM.
You can tune the EDM. It’s not so much that it’s a better system, but that you can (very accurately, better than 1%) calibrate it.
Once calibrated, it is uncannily accurate. “How much do you want?”, “Oh fill it up, 387 litres please.” 
Sure; every flow totaliser instrument has what they call a K-factor which is the conversion from the number of pulses from the transducer (which for the Flowscan 201B typically used is about 28000 pulses per USG) to the reading on the instrument.
Zuutroy’s post suggests this was done for one and not the other.
But using one transducer to feed both instruments is prob90 a bodge. I have had several avionics shops do this in other contexts. The problem is that the transducer has an open-collector output so the instrument has to provide a supply to it, and while it is possible to arrange this (with some diodes and resistors) so that either instrument can provide the supply, almost no avionics installer will know this, and the result is usually that powering down either instrument will kill the output signal. If the two instruments are on separate buses that makes it even worse because you may power down one bus due to a fault, etc.
Some of the Shadin instruments have switches to set the K-factor and it can be set only in discrete steps which can be a hassle. I have one of those but fortunately it is spot on.
The EI CGR30 I have has never struck me as a dreadful UI so I guess that’s a step forward over the JPI. Newer design.
Howard wrote:
I have an EDM700, and so I share your pain Timothy, and perhaps it’s worse with the historic 700 compared with your shiny 960 model.The fundamental problem with the EDM700 is that the EDM people designed the panel with just two buttons. The device then presents many different puzzles to the user beginning at start up with “Refuel y/n?” and one then has to remember which button means yes and which means no. (They are helpfully marked “Step” and “Lean find” to assist you.)…and one also has to remember the incredibly puzzling key sequence if you have added fuel (yes) but have not filled the tanks to the top (hmmm).
The system also adopts various modes of operation many of which are without any enumerated indication. These are largely accessible via a combination of long and short presses of the keys marked Step and Lean Find, despite not being step or lean find operations.
The EDM700 manual is of course rather useless, having been written or supervised by the same team that designed the panel, but sadly, unlike Toshiba laptop manuals from the 1980s, the EDM manual contains no unintended jokes good enough to leave the user gasping for air whilst laughing uncontrollably. The EDM manual is just poor.
We need to start a pressure group to get this company to start listening
This made my day :) Hilarious and so frigging true….
EuroFlyer wrote:
This made my day :) Hilarious and so frigging true….
Pilot
EuroFlyer
Absolutely! The buttonology of the EDMs must be the worst design – ever. Have to say I laughed out loud upon reading Howard’s post!
