Not sure if this is related to the SL30 problems but when designing my panel I ran into what I considered an ambiguity or potential problem with the way Dynon suggests connecting the EFIS, EMS, GPS and SL30. Dynon states the EFIS and EMS should be connected to each other via the DSAB bus PLUS via a null modem connection on the primary serial channel to allow the EFIS and EMS to share screen data. If you have both a GPS and SL30, they recommend connecting the GPS to aux serial channel receive (pin 19) on the EMS and the SL30 to serial channel receive (pin 22) on the EFIS. This configuration allows the EMS to display an HSI sourced from the GPS and the EFIS to display a HSI sourced from both the SL30 and GPS. Well?. Connecting the SL30 to the serial input of the EFIS could be a problem since they already have you connect the EFIS and EMS primary serial channel together with a null modem. So, you end up with both the EMS and the SL30 driving the same serial line which is a no-no unless the electronic interface is designed for such and a communication protocol allowing communication is used which I?m sure is not the case. You would also need to be able to disconnect the SL30 when performing firmware updates on the EFIS.
To avoid the possible problem I decided to connect both the GPS and SL30 data outputs to the EMS via a SPDT selector switch. This limits you to only using one of the two devices at any one time on both the EMS and EFIS but it avoids the problem of having two devices driving the same serial line.
Perhaps I have missed something in the Dynon manuals. Hopefully Dynon Support will chime in and clear things up.
J.C.