Do More PID

[Henryp]

Does anyone have a sample example of how a PID loop is done in a Do More?

[plcnut]

I "believe" there is a sample located in:

Projects>>Examples>>Do-more Simulator>>PID1

[franji1]

The Do-more Simulator not just simulates the Do-more control engine, it also has a "Process Simulator" that you can enable that takes control over your WX0 (first analog input) to simulate a process variable based on WY0 (first analog output).

The sample project mentioned then utilizes that feature in the Sim to control "the process" via the code in the project.  Just look at the Start Page in that project for details on what it does and what you can do with it.

[Henryp]

Thanks, it seems like a conversion from a 450 to a do more will not be as hard as I thought. The math, analog and PID functions seem to work well without a lot of code or hassle.

[franji1]

Thanks, it seems like a conversion from a 450 to a do more will not be as hard as I thought. The math, analog and PID functions seem to work well without a lot of code or hassle.

That's great!

Math is much simpler (one MATH box where you can mix and match decimal and real values in Excel/Basic/IBox-like expressions). 

Analog "just works" - it shows up as WX/WY, just like discrete X/Y in classic DirectLOGIC PLCs.  No pointer method setup.  Definitely no multiplexing.  No logic whatsoever (WX0's value contains the first analog channel on your first analog input module, just like how X0 contains the first discrete input point on your first discrete input module; and yes, WX analog input values are live even in PROGRAM mode, just like X discrete input values are live in PROGRAM mode).

PID is much more flexible via the PID instruction, along with separate Ramp/Soak, High/Low Alarm, Rate Alarm, Filter instructions (and more), providing a simple software interface, but powerful toolbox for your process logic.