Salary discussions during interview

“How early should salary discussions take place in an interview?” I posed the question first along with a brief description of the events for background info.
I was called by a potential employer to interview for a new position that was posted onlyto internal candidates. Since it was only posted internally I had no previous knowledge about the duties/responsibilities. This site has been going through a major re-org with the goal being centralized services. I have an afternoon of interviews set up with the three top vp’s. I don’t want to waste my time or theirs if the salary is not even in my range.