TwinCAT 3 help needed


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I'm a complete beginner to TwinCAT 3 and more generally, working with PC based automation software (I am a chemical engineering undergraduate).

I'm looking to develop some code that will be able to do some basic IO interfacing and provide some sort of output to a user based on its readings.

I'm not sure how to go about this is TwinCAT 3, mainly from a, 'how do set up and test such a system in a virtual environment, without physical IOs to begin with?' standpoint.

I've looked at the documentation on the Beckhoff website already but still need more guidance.

Any advice or literature suggestions would be greatly appreciated. Literature on Function Block Diagrams would also be very useful



There is a tutorial for TwinCAT 3 on their website. I haven't moved to it yet since waiting to upgrade to Visual Studio 2010, but I do have a CX2030 with TC3 runtime. I know you can install it for practice on your PC w/o a PLC, but haven't tried. They also have a time simulation mode, which a ChE should appreciate.

I suggest starting with Structured Text (ST), since closest to Basic, C, or whatever text language you learned in college. Function Block Diagram (FBD) is popular for motor control, or anywhere you call many pre-built functions. It is similar to LabView in looks. I call PID blocks in ST, since many cryptic inputs and the graphical adds no value. In ST, I can comment inputs easier. I have used FBD to call timers and such, where the graphics makes it look simpler. Your main POU can be SFC to control the overall flow, and let each block be ST, FBD, LD, or CFC as you prefer.

If you figure out CFC, let others know. It looks like higher-level graphical programming than FBD, but not widely used, at least in the U.S. There is a good text by 2 Germans on IEC 61131-3 ("Programming Industrial Automation" or such) that is very detailed. It emphasizes constructing re-usable objects and structures. They also promote CFC.