Which function of AVIC-Z1 possible to control with SWI-PS interface? Any way I can initiate voice function through SWI-PS?

Your choices are:

1. Volume Up
2. Volume Down
3. Mute
4. Track Up/Seek Up
5. Track Down/Seek Down
6. Source
7. Preset Up/Disc Up
8. Preset Down/Disc Down
9. Band

So there no way I can have Voice activation instead of Mute?

You might want to email PAC Audio, maybe they have changed the software, but it mimics the wired remote and plugs into the back of the unit. As far as the manual supplied with that unit, those are the "commands" he can send out. You can program your Volume UP button on your steering wheel to be Track down, or your Memory Up button to be source....

But that list is the only commands it can send out to the head unit.

You might want to email him and see if there is a new version, adding new "commands" would be a software upgrade. He might not know about new commands he could send. Maybe if enough people requested new commands then he might included them in the software.

But there would have to be a hard wired remote with that button out there some where that you could buy. If the head unit doesn't think that a hard wired remote would ever have a "voice activation" button, then the PAC adapter can't just make one up. He can only copy what a wired remote already has.

Maybe you could look into the SWI-X, which is IR, it might have other commands it can emulate.