QUESTION
I am using RSLOGIX500 connected to Micrologix1100, sometime, Toggle bit instruction does nothing to XIC (NO) or XIO (NC) contacts, it only changes the bit value in the data file (memory), but does not make any change on the ladder program (No action on the rung )
What is the reason? and how can we resolve it?
REPLIES
xnuke
Read this and see if it answers your question.
Ron Beaufort Training, LLC 5900 Core Avenue, #102 Charleston, SC 29406 843-437-1883 www.ronbeaufort.com
Hands-On Technical Workshops by Ron Beaufort….Beginner Level Quiz #115 – Summing Up When properly used, the “Toggle Bit” and “Force” features are among the most powerful troubleshooting tools that a PLC technician has at his disposal. Unfortunately most technicians have little or no understanding of exactly how these important features actually work. Even some “Top Gun” PLC technicians with years of experience often rely on “hunt and peck” troubleshooting methods which are based on mistakes and misconceptions. As we said before, the reason that the “wrong” answers to our quizzes seem so confusing is that they are based on the same common misconceptions that many technicians believe to be true. Unfortunately much of this material “sounds right” even though it happens to be totally wrong. The fact that these wrong ideas are so commonly believed and so widely circulated helps explain why some people find PLC skills so hard to master.
If you’re interested in how our PLC Boot Camp classes are specifically designed to weed out and correct these types of mistakes and misconceptions, you can find a lot of detailed information on our website at www.ronbeaufort.com. We hope that you’ve enjoyed the quiz – and hopefully learned something from it. We’ve tried to keep the test conditions in our experiments as close as possible to the “normal” conditions that you’ll run into while working in the field. But, as they say: “Your mileage may vary.” Just remember that there are many factors which can affect the results of any test. That’s why it’s always best to learn and understand the “nuts and bolts” of why each PLC system acts the way it does – instead of relying on popular “rules of thumb” which might not be accurate in every situation.
If you’d like to discuss any of the material in our PLC Quiz, just contact us and give us a chance to go over it with you. We’ll be glad to answer any questions that you might have.
SOURCE
https://www.eng-tips.com/viewthread.cfm?qid=442267
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