DL-450 Temperature Control

[allenrogers]

      I have a plastic film extruder with a very old proprietary temperature control system that is no longer supported by the OEM, and want to replace it with something our plant electricians and engineers can support.  I have a 450 PLC and the F4-4LTC module, as well as the F4-16PID coprocessor on hand to do some bench testing.  The loop outputs will be reverse acting time proportional.    An extruder barrel has a very large thermal lag, which makes controlling the temperature more difficult when the feed rate (screw RPM) changes. 
      One of the things I want to try is to modify the "bias" or maybe the output itself when there is a change in the feed screw RPM to "feed-forward" the anticipated new output level to prevent large drops in temperature until the Integral has a chance to catch up.  Typical zone tuning is P= 3.5-5% (gain of 20-30), I = 1500 to 2500 seconds, D = 300 to 400 seconds.
     We recently updated another extruder line with a Red Lion system which has a tendency to go into Integral Windup and has no provision to manipulate the bias or output value directly. 
      The system will have a total of about 80 heat loops, many of which will have dual heat/cool requirements.  The system can be easily divided into two systems of about 40 loops each.  I plan on using a “C-More” touch screen.  At this point I am leaning toward the 16PID vs the 4LTC module, because manipulating the output or bias might be easier. 
      Does anyone have experience with the either the F4-4LTC or F4-16PID module?  Any programming examples or cautions would be very helpful.   

Thanks,