Here's an old post of D10A and 740 settings I use. I'd assume the D100 would be same.
https://www.iflygps.com/Support/Forum...ope/posts#42978
One other note. I have The receive pin on the usb/serial adapter is intentionally removed so that it's not a full null modem - just Tx on iFly to Rx on Dynon. The D10A transmits something that seems to initially confuse the iFly as to what type of device is connected and I had to be bery careful with power/boot sequence until I disconnected Rx to iFly. With pin removed it works every time without being picky about start order. This I found years ago with either my 700 or 720. I am still using same cabke with my 740 now so can't be 100% sure issue still exists with 740b or therefore still necessary , but I certainly have no issues. Try settings, if still problematic try disconnecting Rx pin into iFly. Good luck!
Didn't ask - you connected directly or have an HS34?