I'm trying to extend the functionality of my APC40. To do this i would like to capture the midi data from the device and send it via the IAC driver to Ableton Live. With a second Bus of the IAC driver i would like to pass the signals from Ableton Live via pd to the Device.
But this doesn't work for me.

The first Problem is that I'm not sure if the bidirectional communication works. I've read in this forum that pd uses the first 16 midi channels for the first device and another 16 channels from 16 to 32 for the second device.
So i made the APC40 my first input device and the IAC Bus 1 my first output device. IAC Bus 2 is my second input device and my second output device is the APC40. Then i only connected all midi ins that are described in the help file with the midi outs.
While doing this i've noticed that no sysexout exist.

This leads to the second problem.
APC40 and live do a handshake. but this handshake doesn't work in my case. I think this is because no sysexout data is passed through.

I hope I described my setup understandable and you could tell me if the bidirectional communication works the way I've tried to get it to work and if you know how to make the handshake work.

Mayb one of you has already solved this problem. It would also help me if you know a way to intercept the communication without pd. But it would be great if it works with a free tool.(I know that it could be done with bome's midi translator)