rdarling3599

Logix data tag structure

4 posts in this topic

Can anyone advise if there are data structure #s associated with each of the data types in Logix?  Example if it is a Bool, I believe Logix advises it is a 32 bit number.  But is there an "under the hood" data type reference number for each Logix data type?  I.E.  if it is a Bool, that is a RA data type #1, if it is a DINT, it is a RA data type #2, etc.  

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I don't think I'm following your question but I think the answer is no...   If I create a tag called Larry and it's the DataType Bool[32] I get 32 tags starting with Larry[0]...Larry[31] Or if it's Fred of the type Bool the tag is just Fred Or I can make a UDT with mixed data types (String, Bool, Real, Int, DInt, Timer, Counter... etc) So if I make a UDT called Trisha with the following structure String1 type: String String2 type: String PV type: Real HH type Bool and then create a tag name of AB of the type Trisha I get AB.String1 AB.String2 AB.PV AB.HH A could make the type Trisha[2] and the tags would change to  AB[0].String1 AB[0].String2 AB[0].PV AB[0].HH and AB[1].String1 AB[1].String2 AB[1].PV AB[1].HH

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Logix PLCs are tag-based, compared to SLC & PLC-5 controllers which are I/O-based. Are you looking for a back-door method for accessing tags other than using tagnames?

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Thank you!  Yes I was asking if there was a "back door" reference for the tags.  I do understand the tag structures available but am asking if there is a background tag type identifier? 

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