Avionic connections

uk_figs

Member
Joined
Jun 12, 2007
Messages
38
I am wiring up the D100 and D120 and trying to plan the installation of the wiring for the SL30 and the 496, the included Steinair D100 harness has the 3 connector DB9 for PC update and an additional yellow/green wire for GPS/SL30 TX input, I assume this wire is ganged on pin 22 for SL30 nav data RS 232 input from pin 5 (TxD1) on the SL30, is this correct?
Also as this wire has to be disconnected for firmware updates it suggests I need a switch or connector in this line, is this what most people do? The same pin 22 appears to also connect through the null modem to pin 11 of the EMS (I assume TX to RX for pins 2 and 3 in the DB9 connectors via the null modem) and the instructions have the 496 connected to pin 19 on the EMS which is the aux serial receive. Does this imply that all 496, EMS and SL30 communication comes through pin 22 on the EFIS
If I understand this all correctly, to get full functionality I will need to connect the RS232 TX/RX lines and the DSAB A/B lines between the EFIS and EMS, is this correct? Which functions transfer between the EFIS and EMS through which communication path
Sorry for the lengthy post but I am trying to get the picture before I run wires.
Dave
 

dynonsupport

Dynon Technical Support
Staff member
Joined
Mar 23, 2005
Messages
13,226
Ok, first things first:

Currently, the EFIS transmits data to the EMS via the serial line. The EMS transmits to the EFIS via the DSAB wires. You may connect only one set if you wish to have only uni-directional swapping.

We are already in beta on firmware that uses ONLY the DSAB wires for communication. If you're not going to be flying in the next few months, just wire the DSAB wires and don't worry about a null modem at all.

If you do use a null modem, it needs to hook only the TX from the EFIS to the RX of the EMS. This is because you can't have the EMS TX hooked to the EFIS RX or it will mess up what is connected to the EFIS.

Second issue:
You need to hook your SL-30 to one unit (EFIS or EMS) and the GPS to the other unit. Today we'd recommend the SL-30 into the EFIS and the GPS into the EMS, but with this next update, it won't make any difference, and we'd suggest wiring the device you feel you need the most directly into the EFIS in case the EMS ever fails.

Basically, here's what we'd recommend today for anyone that won't be flying in the next two months:

Wire DSAB between the units. You can verify you got this right if you can see the EMS on the EFIS.
Wire your SL-30 into a DB-9 connector and plug this into the EFIS PC update port. This way you can just unplug it while doing updates instead of installing a switch.
Wire your GPS into the EMS pin 19.
Update to version 4.0 software when it comes out.
 

uk_figs

Member
Joined
Jun 12, 2007
Messages
38
Great reply, thanks :). I will not be flying for a while so this helps a lot. I assume therefore the I can ignore the yellow/green wire on the steinair harness and wire the SL30 to pin 3 (EFIS serial Rx) of a DB9.

Dave
 
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