PID.vi question

[PiMaster]

---

gwd wrote: -I had the lamp going full blast for a second or two.  Which caused one of the guys here to (justifiably) freak out. Well it pays to be cautious but some people are just too panicky to stand next to a process tool.

---

You may very well be right, but lets just say I am not in the position to make such observations. Anyway, I was already gonna just limit the maximum power the lamp can take and see if I still got satisfactory performance.  I imagine it wouldn't be a problem.  I just wish I didn't have to do the setpoint profile thing, but it's kinda been micromanaged in there.  Having that specific ramp rate seems vestigal to me (it was part of the old recipe), and something that 99% of the prior users of the tool weren't even aware of, much less overly concerned with (as I've been told).

My problem is what it is, though, and it's that I can't get the PID to respond with that setpoint profile in a conventional way.  And if I were to place just a simple constant setpoint in that very same program I posted it would work like you would expect.  So I assume I am doing something wrong.

Oh yeah, another problem is that the pyrometer is apparently not on a linear scale, and the Peak documentation seems contradictory and aloof about calibration, aside from using the (now gutted) proprietary Peak control system.  I managed to crack the Peak provided "RapidThermocouple" wafer today at a mere 1000 C (it was supposed to be C type).  I think it's safe to say we won't be getting another one from them.  The good news is that we're getting an R type replacement (which the TC-120 will do conversions for).  The bad news is it won't be here for a few weeks.  But I guess none of that is a LabVIEW problem

Message Edited by PiMaster on 05-11-2006 07:30 PM

[PiMaster]

I figured out my main problem.  For the time values, I had put in values relative to my dt.  For instance, if I wanted 2 seconds, I would have put in 200, since my dt was 10 msec (now it's 5 msec, but that's beside the point).  Oops.  It works now that I put values in as seconds.


Also, I was not expecting the setpoint profile to ramp the setpoint.  I figured it just would have changed the setpoint once upon each change in the setpoint profile.  This actually works much better for our purposes.