I have a D10 upgraded to a D10A installed in my RV4, with EDC. I got another D10A to provide an HSI display (no room for a D100) and to act as a backup EFIS. Understand DSAB should handoff info between units under normal conditions, but what happens on backup EFIS if main D10A fails? Of particular concern is the EDC info and the serial output to transponder. Also is the same software update required on both units?
Double D10A
- Thread starter Feetwet
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- Mar 23, 2005
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Dual EFIS-D10As can share data, but they're not designed to be redundant, with handover in case of failure.
To accomplish full redundancy, you would need to install an EDC-D10A for each unit, and a switch for the serial altitude input on the transponder from each EFIS-D10A. The switch can be a simple Single Pole Double Throw (SPDT) toggle switch as the serial interface to transponder is one wire.
To share data, both units have to have the same version of firmware (SETUP > VRSION) and have the DSAB wires connected together.
To accomplish full redundancy, you would need to install an EDC-D10A for each unit, and a switch for the serial altitude input on the transponder from each EFIS-D10A. The switch can be a simple Single Pole Double Throw (SPDT) toggle switch as the serial interface to transponder is one wire.
To share data, both units have to have the same version of firmware (SETUP > VRSION) and have the DSAB wires connected together.
Normally, only the "master" EFIS's - the one you performed your DSAB configuration from - EDC provides heading to the entire system if you have them connected via DSAB. If that EFIS fails, the other EDC would take over for its own EFIS if it's also been calibrated. I'd recommend, after you've gotten everything set up, "failing" each EFIS by simply turning each of them off to make sure everything is set up right.
The serial output to the transponder is tied to the EFIS whose serial output line is connected to the transponder. You can't connect both EFIS's transmit lines to your transponder - they'd interfere with each other electrically. So if that EFIS fails, you'd lose your altitude encoding to the transponder. (As an aside, SkyView has a unique and more advanced architecture that lets EITHER display feed serial data to external serial receivers like transponders, allowing you to connect all serial lines in parallel. This means you lose NO functionality should one of two SkyView displays fail in your aircraft.)
The serial output to the transponder is tied to the EFIS whose serial output line is connected to the transponder. You can't connect both EFIS's transmit lines to your transponder - they'd interfere with each other electrically. So if that EFIS fails, you'd lose your altitude encoding to the transponder. (As an aside, SkyView has a unique and more advanced architecture that lets EITHER display feed serial data to external serial receivers like transponders, allowing you to connect all serial lines in parallel. This means you lose NO functionality should one of two SkyView displays fail in your aircraft.)
Thanks guys, that was what I suspected. I was considering trying to send both serial outputs to my tt31, but then even if it worked I would have no rs232 input available for eventual certified GPS input for 2020. I think I will just use the internal compass on the stby EFIS and accept the loss of altitude to transponder in the unlikely event of loss of master EFIS.
I will bring both units up to latest firmware. Hopefully that will solve the below 11.5v failure to turn on issue I had with my original D10A. Looks like 5.4 should have solved that. FYI, my fix was to get an automotive computer 12v power transformer, wire it in ahead of the D10, and kick up the voltage to ~16v. It has worked for 4 years, but is an additional failure point.
I will bring both units up to latest firmware. Hopefully that will solve the below 11.5v failure to turn on issue I had with my original D10A. Looks like 5.4 should have solved that. FYI, my fix was to get an automotive computer 12v power transformer, wire it in ahead of the D10, and kick up the voltage to ~16v. It has worked for 4 years, but is an additional failure point.