wildswing
Member
Hi fellas,
I've just learned of an upcoming project that I'm going to be asked to do the programming on. Details are very sketchy at this point. Here's what I've been told. Project is a new resin (glue) injection system in our MDF mill. Resin is injected into the fiber blowline immediately after refining and before drying.
The physical system includes 80 identical injection nozzles, each with it's own analog valve and some other stuff. What I'm told is that this will require 80 PID loops. I'm hoping that's a typo, but it's all I've got to go on for now. My heads racing trying to think of a way to not write 80 identical pieces of cookie cutter ladder logic [note: I have no SFC and very little text based programming experience. I'm an old PLC5 ladder guy]
One idea I've had is to put the PID in a subroutine and then go to it 80 times, but wouldn't that bugger up the PID? Could I change the PID address each time through using an indirect (or clx equivalent).
Like I said, initial details are very sketchy, but now that I know I'm in for a boat load of work, I'm beating the door down for more specifics. Thought I'd get the juices flowing by posting now.
Any guidance or advice you may have would be greatly apprecaited.
I've just learned of an upcoming project that I'm going to be asked to do the programming on. Details are very sketchy at this point. Here's what I've been told. Project is a new resin (glue) injection system in our MDF mill. Resin is injected into the fiber blowline immediately after refining and before drying.
The physical system includes 80 identical injection nozzles, each with it's own analog valve and some other stuff. What I'm told is that this will require 80 PID loops. I'm hoping that's a typo, but it's all I've got to go on for now. My heads racing trying to think of a way to not write 80 identical pieces of cookie cutter ladder logic [note: I have no SFC and very little text based programming experience. I'm an old PLC5 ladder guy]
One idea I've had is to put the PID in a subroutine and then go to it 80 times, but wouldn't that bugger up the PID? Could I change the PID address each time through using an indirect (or clx equivalent).
Like I said, initial details are very sketchy, but now that I know I'm in for a boat load of work, I'm beating the door down for more specifics. Thought I'd get the juices flowing by posting now.
Any guidance or advice you may have would be greatly apprecaited.