Photos of Rotax >> Dynon CAN wiring?

Page 9 of the Van’s wiring diagram for the RV-12iS shows their HIC interface module.  They tie the A & B CAN bus lines together in the module then connect to the HDX.  It works just fine.

https://www.vansaircraft.com/wp-content/uploads/2022/10/WH-00133-1.pdf

A couple of things. make sure you have the newest version of BUDS. If this doesn't work try changing the Baud rate down in the menu. Make sure all power, keys and ignition switches are in the on position and see if this helps.

Bob Yanniello wrote:

Page 9 of the Van’s wiring diagram for the RV-12iS shows their HIC interface module.  They tie the A & B CAN bus lines together in the module then connect to the HDX.  It works just fine.

https://www.vansaircraft.com/wp-content/uploads/2022/10/WH-00133-1.pdf

I don't have that module, whatever it is. I'm referring to the Dynon Installation Manual page 7-36, which also shows A & B tied together, then connected to the HDX. Doesn't work.

"make sure you have the newest version of BUDS. If this doesn't work try changing the Baud rate down in the menu"

I don't have the BUDS dongle or software. Just trying to get the Rotax and the Dynon to talk to each other in a new install.

Start Power and/or Backup Power can be on, engine can crank, other sensors can feeding data through the EMS-221, just no CANBUS info.

The Engine will crank with the ECU OFF (Lanes Off).
The Fuel Pumps will pump with the ECU OFF.
The Engine cranks and Fuel Pumps through the Fuse Box, Not the ECU.

Assuming your LANE Lamps illuminate for 3 seconds after turning ON the Lanes...   <---<<<  ***

Be sure the CAN bus is wired properly.
ALL the CANH pins tie together and all the CANL pins do the same.
it is NOT CANH to CANL.

The LANE-A CAN is one end of the Bus and LANE-B is the Other (Far) end.
Each LANE end already has the 120Ω resistors present.
No additional Resistors are needed.
Your HDX/EMS is technically in the middle of the bus.
Ideally, the A and B CAN Buses should tie together AT or very near (within 1 ft) of the EMS connector.
If your A and B Buses tie together and then travel 6 ft to the EMS, this can be the problem.
Measure from Pin 36 to Pin 37 on the disconnected 37 Pin EMS Harness connector. 60Ω is correct.

Assuming the LANE Lamps function, the most likely cause would be the CAN Polarity.