Hello ! I understand that CAT is not yet fully ready.
When I use latest "VarAC_cat_commands.ini" with ft847 the 847 appears in PTT (still PTT doesn't work) but not in Frequency control (so also doesn't work).
With both OmniRig PTT and Frequency are working, but I must kill Omnirig (Task Manager) to get the serial com port free when I end with varAC - OmniRig usually doesn't close with closing varAC.
CAT would be nicer then Omnirig to avoid this process-killing-issue.
Freq control for 847 is on my todo list. a bit more complex. As for PTT - it should work and I got reports from others that said it works fine for them. I invite you to post this question on our FB page where we have 1300 users while some use FT847, and see how they did it.
Make sure you use the right RTS/DTS as some Yaesu rigs requires RTS/DTR high for CAT commands.