Bad memory. The EC3 display connection to the remote Data Acquisition Module is not serial. The serial connection is between the Data Acquisition Module and the EC3.
TB4-1 OAT BIAS BLACK LEAD ON OAT SENSOR
TB4-2 LYC. TACH P-LEAD ON MAG (Lycoming only, no ec3 controller)
TB4-3 TACH & FUEL FLOW SENSE FUEL INJECTOR 1 LEAD ON EC3 & FUEL INJECTOR
TB4-4 SERIAL DATA IN SERIAL OUT FROM EC3(J2-13) or EC2(J1-7)
TB4-5 N/C
TB4-6 N/C
TB4-7 GROUND GROUND ON AIRFRAME NEAR AQM
TB4-8 +12 POWER AVIONICS POWER BUS (SWITCHED)
TB4-9 VOLTAGE SENSE MAIN POWER BUS (TO SENSE SYSTEM VOLTAGE)
TB4-10 SERIAL DATA OUT SERIAL IN TO EC3(J2-12) or EC2(J1-27)
TB4-11 N/C
TB4-12 DISP DATA OUT PIN 5 ON EM3 DISPLAY CONNECTOR J1
TB4-13 Vss/GROUND PIN 17 ON EM3 DISPLAY CONNECTOR J1
TB4-14 DISP DATA IN PIN 7 ON EM3 DISPLAY CONNECTOR J1
TB4-15 DISP DATA CLOCK PIN 6 ON EM3 DISPLAY CONNECTOR J1
TB4-16 +5 POWER FOR OAT SENSOR RED WIRE ON OAT SENSOR
Bobby
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
Sent: Monday, February 08, 2016 9:08 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: [Flyrotary] Re: Testing
Hi Bobby
I can easily disconnect the dynon and test, so I’ll try this.
I think I used the Dynon low voltage RPM input and I might change it to the Standard Input.
I’m not sure I understand your last sentence. Are you referring to the EM3 Data Acquisition Modules count of Inj #1 used for Tach and Fuel Flow calc.
Steve
Have you tried disconnecting the Dynon Tac signal lead from the injector pulse to see if the EC3 reads correctly? Since both units are showing the same rpm it’s possible the injector is being held open by the Dynon. See Bill Schertz post from 2012.
Since the only connection between the EM3 screen and remote is serial then I would assume the rpm pulse count is correct.
“The reason that I asked the question about idle on the secondary injectors is that when I first started the engine, with a Blue Mountain EFIS, I found that the engine ran very rich on the primaries, which were preferred by the EC-2 at idle, but when I switched to the secondary injectors the engine smoothed out. This led to the investigation of why, since all my injectors were the same size. I then found the problem with the BMA tach signal holding an injector open (or causing it to close slowly) that was fixed with Tracy’s recommendation of a 2K resistor in the line to limit the current draw from the BMA.
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
Sent: Sunday, February 07, 2016 6:42 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: [Flyrotary] Re: Testing At this stage the prop is not constant speed, just adjustable.
So I could do I similar thing. Choose an Rpm.
Why was the 2100 RPM at the prop chosen? Did you determine this to provide
Our EM3 RPM reading issue appears to be related to inj #1 signal as the reading goes intermittent and low (from memory ~ 800 RPM) and the Skyview suffering the same.
Does your prop have a constant speed controller or is it strictly manual operated? One or possibly two folks flying MT electric constant speed controllers have reported an rpm difference between the selected prop rpm and the actual engine rpm. Mine is very close.
Has anyone else had the EM3 read rpm incorrectly at high RPM?- My EM3 screen sometimes shows the correct rpm and then NOP and alternates every second or so. Reducing rpm seems to correct the issue. I suspect it’s noise on the serial circuit. I plan to replace the serial wiring with shield wire next time I have the panel out. My AFS EM show correct rpm at all times and it reads the same injector pulse.
One other thought regarding tuning for 7500 rpm. Initially I had a lot of trouble tuning with the constant speed electric prop. Tracy recommend I run up full power, adjust the prop for 2100 rpm, lock it in manual mode and tune at this condition. This made tuning easier since I wasn’t chasing the changing prop loads. If your prop controller is manual only then you may not encounter the same difficulties.
It's an Electric 3 blade Aerotek from New Zealand.
In order to extend ground testing and tuning of the engine in 35+C (95+F) I rigged some water spray onto the water exchanger.
Water temps now stay below 150F even at high load, and to my surprise Oil temps stayed below 180F (I thought I might have to spray water on the Oil Exchanger but not required)
I reduced the pitch of the prop to allow a static rpm of approaching 7500rpm and without much missing she spun up OK.
I feel like Im starting to get familiar with the EC2 now and between MODE 2 and 3 and just manual mixture adjustments she runs from idle to 7+K alright.
One observation is that at around 6-7K RPM both the Dynon Skyview as well as the EM3 fail to read the RPM correctly.
Now they are both taking their sensing from Injector 1.
The EC2 of course gets its trigger signal from the Renesis CAS’s (main and backup) and there is a mod on the back of the EC2 board that I took was conditioning of the CAS signals.
Has anyone else had the EM3 read rpm incorrectly at high RPM?
After balancing our prop, I’m hoping to begin playing with the EC2’s closed loop mode, and then Timing with new BR10EIX plugs.
Thanks again Tracy for your gearbox and EC.