I see on the user manual of your rig its very similar to my FT-840.
On p31 in the manual it explains the data flow, with one start bit, 8 data bits and two stop bits, no parity or flow control.
I also see on p34 in the paragraph sending a command it mentions that the data rate is set to 4800 baud so your Virtual serial port should also be on 4800 baud, otherwise the data comms may be to fast. Check again the stop bit is set to 2 and not 1.
--
73 de Eugene / ZR4EM
ZR4EM / Eugene