Absolute addressing on AB PLC

4 posts in this topic

Good day.

I'm using 1756 L71S GuardLogix Integrated Safety Controller with Studio 5000 v28.

My controller is connected to a third party software through ethernet connection, it simulates my project hardware and provides all the signals to my PLC. To know all the hardware signallocation at PLC memory, it uses a Tag export file provided by Studio 5000.

In other PLCs, when you declare a variable as hardware input, you have to select in which address from the memory you want this input to be read, something like "Bit Input 0.0". But in AB this step is skipped, that is all addresses are managed by Studio5000 and hidden from the user.

Is there any configuration at Studio 5000 that let me assign or at least see this addresses?

Normally I would prefer my tags addresses to be hidden, but in this specific case it is more useful to know memory addresses.


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I’m not aware of anyway to see the level addressing that I think you want to see. Ie Tag Bool resides in some absolute memory address In the microprocessor and you want to see it. 

Even Mel’s reference to Local: for IO isn’t the actual physical level address of the microprocessor IO. It’s just a pointer. 

I think that knowing hardware level memory addressing would pose some level of security risk

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Try creating an Alias of the Local tags. Right click on a Local tag and choose, New tag which aliases "Local:1:I.Data.0" for example.

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