recondaddy
Member
Hello everybody!!
Since my last post, I've started a new job as a manufacturing controls engineer (plant job). I spent the previous four years working for a systems integrator (Rockwell Solutions Provider). As such, my only experience was with Rockwell products and ladder logic.
Since I've taken this new position, I'm suddenly in charge of maintaining and improving everything from PIC-controlled machines (line-by-line programming), distributed motor controllers (line-by-line programming) Steeplechase-controlled machines (flowchart programming), and ladder logic. It's been a helluva lot of fun learning the vast array of different technologies.
It's also been educational, now that I've been exposed to other programming methods, to see the subtleties between the various methods. For those of you with experience in more than just ladder logic, I'd like your insights, as well.
Looking at the way ladder logic executes, it is scan-based, and the cycle for solving logic is performed by reading all the inputs, processing user logic (solve the rungs), and then writing the outputs and updating registers.
So, it has the ability to deal with multiple machine processes in a parallel fashion (all at one time). Is there really any way that such behavior can be mimicked in line-by-line programming (PIC microcontrollers) or in flowchart programming? Or, are these methods strictly for use in step-by-step applications?
I can see where seemingly parallel operation could be achieved by distributing several programs throughout separate controllers on the machine, but can PLC behavior be implemented with only one controller?
Thanks!!
P.S. Is there another term for the type of programming we do in PICs besides "line-by-line"?
Edited to add:
I guess the better question to ask is, "Can simultaneous control of multiple machine processes be achieved with a single line-by-line or flowchart program?"
Since my last post, I've started a new job as a manufacturing controls engineer (plant job). I spent the previous four years working for a systems integrator (Rockwell Solutions Provider). As such, my only experience was with Rockwell products and ladder logic.
Since I've taken this new position, I'm suddenly in charge of maintaining and improving everything from PIC-controlled machines (line-by-line programming), distributed motor controllers (line-by-line programming) Steeplechase-controlled machines (flowchart programming), and ladder logic. It's been a helluva lot of fun learning the vast array of different technologies.
It's also been educational, now that I've been exposed to other programming methods, to see the subtleties between the various methods. For those of you with experience in more than just ladder logic, I'd like your insights, as well.
Looking at the way ladder logic executes, it is scan-based, and the cycle for solving logic is performed by reading all the inputs, processing user logic (solve the rungs), and then writing the outputs and updating registers.
So, it has the ability to deal with multiple machine processes in a parallel fashion (all at one time). Is there really any way that such behavior can be mimicked in line-by-line programming (PIC microcontrollers) or in flowchart programming? Or, are these methods strictly for use in step-by-step applications?
I can see where seemingly parallel operation could be achieved by distributing several programs throughout separate controllers on the machine, but can PLC behavior be implemented with only one controller?
Thanks!!
P.S. Is there another term for the type of programming we do in PICs besides "line-by-line"?
Edited to add:
I guess the better question to ask is, "Can simultaneous control of multiple machine processes be achieved with a single line-by-line or flowchart program?"
Last edited: