9 - Solution: Step-by-Step Analysis (AB PLC Training)

[jjohnsice]

never had any experience with plc logic, was able to understand completely how the sequencing works by watching 1-10, really very easy, had to get confused if you take it step by step as you show it.. thnks

[WiremanHelp]

Your videos are always so informative and simple. You have a great gift of taking the confusing and making it amusing, but more important understandable

[CaSCHWANK]

Wow. Again, so helpful. Thanks!

[cyberman9000]

Hi Ron, total beginner here.... you said that during the processing the bit for switch A goes back and forth from 0 to 1. I thought that it would start as 1 on rung 1, go to zero on rung 2, and stay as zero on rung 3, and then still be zero when it goes back to rung one, and stay as 0. I thought the ladders just looped. Maybe at the end rung it all go back to "Step 1" and examines all the inputs again which writes the 1 back into the switch A bitbox, and then do step 2 ladder?

[RonBeaufort]

"... and then still be zero when it goes back to rung one, and stay as 0." No, but you were fine up to that point. "Maybe at the end rung it all go back to "Step 1" and examines all the inputs again which writes the 1 back into the switch A bitbox, and then do step 2 ladder?" YES, that's the way it works. If you still have questions, join one of the free public forums on the "Resources" page of my website. YouTube comments only allow us 500 characters – so we can't go into much too detail here.

[bartp84]

quite interesting to see , but i never had this type of problem because it has absolute no sense to set an input as an output.

The thing about the green indicators is idd confusing. So better just to think for yourself then look at the green indicators

Thanx

[RonBeaufort]

Greetings bartp84 ... I'm sure you realize that the idea is to use the "OTE controls an INPUT" trick to demonstrate how the scan works under the hood of the PLC ... so it's intended to be a teaching tool and not a recommended programming technique ... even so, once in awhile the problem does show up as a typographical error ... thank you for your comment ...