Taz

Hi All, Thank you very much for your suggestions! I have a pretty good idea now how to tackle this application. What you guys gave me here will keep me busy for a while. Your help is much appreciated. Joe if you don't mind I will send you some sample values and a basic graph I want to implement. Having a basic program to start with would be fantastic! Regards, Bogdan

Hi, I am designing an annealing oven using V350 and I was wondering what would be the best approach to my application. The temperature has to be plotted against time, with predefined levels and it will be a combination of ramp-ups, plateaus and ramp-downs. In all the sections of my temperature graph I need to avoid sudden fluctuations, since the samples I am working with are very small and sensitive to sudden changes (I will be pushing the temperature close to the material melting point so I need a very low oscillation amplitude around the prescribed temperature; the same scenario applies to the ramp-ups and ramp-downs in order to avoid sudden re-crystallization of my samples). To cut a long story short I need to control the ramps (during the warming up), the plateau (during the annealing) and the slopes (during cooling off) as smooth as possible. The heat will be provided by infrared heaters controlled via solid state relays, while the temperature will be monitored through thermocouples. I am thinking of using the PID option on my PLC, but not too sure how to do it for my ramps and slopes (which again are time based - e.g. temperature should rise from 30oC to 60oC in 30 minutes). Any hints/tips will be much appreciated. Thank you, Bogdan