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Old March 31st, 2010, 03:31 PM   #1
AJZ
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Step7 Reading from IDB STAT area

I am modifying a large STEP7 program with many FBs and FCs. The original programmer is reading STAT bitw of IDB's in other blocks directly using DBxxx.DBXxx.x. Isn't that a very bad practise? If I add or remove IN, OUT or INOUT from the FB, all these STATs will move to a different physical location.
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Old March 31st, 2010, 03:44 PM   #2
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No, it is not bad practice.
Just be sure to use symbolic address priority.
Or did you just upload the program without comments or symbols ?
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Old March 31st, 2010, 04:03 PM   #3
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The customer gave the project. Therefore I have all comments, symbols, etc.
I will test and figure out the four different settings for address or symbol priority.
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Old March 31st, 2010, 06:39 PM   #4
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If you change the declaration part of FBs or UDTs, then it is recommended to run a consistency check. All the modified positions will then be updated everywhere in the program.
You cant do that on a running program of course, but that would be the case even if the FB STAT part was not accessed from outside the FBs.
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