temperature controller

[pid controller]

i have made one temperature controller unit for controlling temperature up to 500deg i am using labview 6.0 evaluation software i have implemented pid controller using pid.vi(downloaded from ni.com) i am able to control the tempt up to 100deg with error of +-1 deg but i could not able to control the tempt more than 100deg and also i could not able to find correct pid parameters for the same at higher tempt the error is -40deg maximum please help me in solving my problem
i am waiting for your reply

[JRA]

Could you post your VI here? It's a little difficult to assess exactly what you are doing. Once we get a chance to see it, hopefully we could help you out with this one.

[pid controller]

JRA i am posting my VI as you suggested me on 4/7/2003