PLC help

[CaseyK]

Terry

I don't know what to say.

Congratulations, perhaps.

Eric, NO mustard jokes.

 

[Peter Nachtwey]

Modularity? No timers?

I think Eric solved the problem. I don't think one can make this application simpler. A good system would have timers for time outs for each state as well as a condition or input that must be met. The exception to this is simple dwells or delays that don't depend on inputs. A timeout condition means the input condition that allows the state machine to proceed to the next step has failed. A good state machine will make it easy to diagnose why it isn't working.

 

[Eric Nelson]

I'm pretty sure Terry just means don't use timers to advance the sequence. I'm not quite sure where he's headed with the 'modularity' idea, but I'm sure he'll enlighten us...

A good state machine will make it easy to diagnose why it isn't working.

Absolutely!...

And, a good state machine should TELL you what's wrong with it, without ever needing to look at the program. There is no excuse not to do this, yet 95% of these programs I see, don't...



-Eric

P.S. I don't get the 'mustard' reference, Casey...

 

[bamatki]

I only said I don't recommend using forces, what anyone else does is up to them. I remember my instructor years ago saying be careful when you use forces and know absolutely what impact they will have on the process. When someone is developing a project how can they know what impact these things will have on the machinery that they are working on? Now lets get back to the original post and in context I was trying to explain that you can develop a project using the simulator function (offline), which is already in the software. In that way if you insert timers or other devices you can actually test and see the effect. I have developed entire projects at my desktop pc using this Keyence feature. It can really help with programming when you can test out your ideas at your desktop pc before you even download it into a processor, of course testing on line is still needed but the simulator is just such a valuable tool that I thought the information could help the original poster.