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Old March 16th, 2019, 07:29 AM   #10
Aabeck
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Quote:
Originally Posted by Skidood View Post
Also, for the logic scanned on the first pass, I was wondering if its better to place the first pass rung(s) at the beginning of the main ladder or at the end of it. Seems to me that putting it at the end makes more sense since all the other ladder logic in the program will be over-ridden by whatever is in the first pass rung. If the fist pass is at the top of the main ladder, the ensuing logic instructions in the rest of the program could over-ride it what i want to accomplish in the first pass. Am I out to lunch here?
If there is a chance what is written from a First-Pass could be overwritten later in the scan I would put a XIO First-Pass on the other rungs so they were not processed on the first scan.
Also, Since the First-Scan writes 0 to your N7:0 it could do that first, then the rest of your calculations could be completed the same scan without causing any problem.
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