[ICOM] icom 781 rtty with mixw

[4X6ZK-מוני]

Shalom to all the hams on the list

I have icom 781 with linear amp ic2kl and antenna tuner ic 500 connected in
line.

I want to connect the 781 to a computer  and to work rtty with mixw program,
after connecting the ci-v level converter I have a good reading of the frq
but I cand get the transceiver to go ptt via cat command.

Acc1 and acc2 are in use by the linear and antenna tuner.

Is it possible that 781 cant get ptt via cat command?

How can I connect the 781 to get ptt from computer?  In my case?

If you can help me please do so and if you can send me some pictures of the
connections will be very helpful 

Thanks and shalom

Mony 4x6zk