Clay B.
Lifetime Supporting Member
I wanted to say something but I let it pass. I was once asked "Why would you do that in the motion controller when you can do it in the PLC" I get along fine with S7 but I don't get to advanced. Have you looked at the S7-1200? It's their new low end controller but I think it will replace the 300 & 400 in a few years. It is only ladder now but they do have blocks for working with arrays.
Yes the 150 is in my demo machine and I have a scale connected and working. If I can find something for a feeder I will give it a test.
We have built several weighing systems using the S7-200 PLC with a MS module. It will do everything that is required of this job.
Anyway...using an axis controller seems like overkill to me. You have multiple manufactors that deal strickly with weight control and AB or Siemens or Unitronics for that manner have onboard weight controllers.
When you use an exisiting weight controller, things like Rate of Change, Preact, Auto preact, tare tolerances, zero tolerances..etc.. etc are already built in... so you do not have to create your own.
Maybe stupid remark, isn't the vibrating feeder a slow stopping something?
Short answer: Yes
Vibration feed can be very tricky depending on how the vibration is made. You can get irratic behavior at various speeds. Usually if I have a system that uses vibration feed I will pick a VFD where I have lots of "skip" frequencies or if I am driving the drive with a PLC I will skip those in my program.
Best system when using vibration feed is to have some sort of valve so you can shut feed off before vibration stops and use vibration for rate.