RMA
Member
I've got to realise a ph-Control system for my current project and I intended to use a system I implemented successfully on an S5 system about 15 years ago in a waste-water treatment plant, where I simply ramped up the output (in that case a VFD controlled feed-screw, in this case a variable-stroke pump) and when the SP and MV differed by less than a certain value (obtained by trial and error) stopping the ramp and re-starting from zero. By using two ramps, effectively coarse (when SP and MV were wide apart) and fine, I was able to get things so that the control was well within the required limits.
Unfortunately, for various reasons, the customer would like me to use FB41 for the basic control, which wouldn't be a problem except for the fact that I can't fathom out how to (effectively) re-start the Integral action timer.
Anybody got any ideas?
Unfortunately, for various reasons, the customer would like me to use FB41 for the basic control, which wouldn't be a problem except for the fact that I can't fathom out how to (effectively) re-start the Integral action timer.
Anybody got any ideas?