Load cells? Speed programmed winder mode? Ouchies.
I'll be 100% honest here, while it is absolutely possible to do a load cell controlled web winder in speed mode, 99.9% of the time it is 37.8 times harder then doing it in torque mode. Why? Tension = torque. Sure, there are some more numbers to fill in, but Tension still equals torque. Speed does not, and the speed loop will bounce all over to make a 0.01% correction, causing wild fluctuations in tension, even if you don't see them. Be that as it may, the best approach for a speed programmed winder (and I hate that terminology btw) is:
-- DISABLE ANY LOAD CELL TRIM FOR THE FOLLOWING:
1) Absolutely know your core diameter, set this to be the MINIMIM value for your diameter calculator. Never let the diameter calculator go below this value, ever.
2) Have a stable, actual line speed value, and a stable, actual winder speed (spindle RPM) value. Sometimes, for line speed, it actually makes more sense to use the reference then the actual speed.
3) For your diameter calculator, don't be afraid to filter it. If you have the option on the diameter calculator, only allow it to INCREASE. Oh, get familiar with the units. I don't remember how SSD/Parker does things, I haven't used canned drive-based winder packages in a long time.
4) Make sure your core speed match is dead on. Use a hand tach to measure the core surface speed as you accel and decel the line. Make sure the speed tracks.
5) Set your MIN CORE VALUE to whatever your max diameter is, load a roll of that diameter if you have it. Again, run the line up and down, and make sure the surface speed tracks.
6) Return the MIN DIAMETER setting to your smallest core diameter. If you run on multiple cores, you should probably use a digital input to set an alternate min diameter here. Digital inputs should also reset the calculator when the roll has been changed.
7) Now you can re-connect the load cell control, and start playing with it's PID. First, obviously, is make sure it responds in the correct direction... Set the maximum trim to something like 5%(*) from the tension control PID, run the line (empty), give it a zero speed reference, and mid range tension reference. The roll should turn at 5% drive speed in the winding direction. Manually load the load cell roll down, the winder should slow down, stop, or possibly reverse. That is good.
8) Have the winder drive set to sum in the output of the tension regulator to the master line speed reference, and then feed the sum into whatever is dividing your line speed by diameter before feeding that reference to the drive.
9) Play with the PID tuning as you slowly bring up the line speed.
(*) - Allow the PID to have a full +/- 100% trim output, but feed that into a multiplier so you can limit it before summing to the line speed reference. The smaller the trim value, the better generally with SPW's. I typically shoot for no more then 2 to 5%.
The above is very basic, but might help you get started.