FB memory area & counting

[pszczepan 2]

Hi ! I try to find relationship between required memory of some FB in its properties and variables which I use for Internal, Input, Output. F.e In properties-> memory I have just "5" Non-retain Internal - no address Input - 2xbool, 4xUint Output - 2xbool Why FB needs "5" How the CX-P counts that? thanks Pawel

[BITS N BYTES 66]

Which model PLC? Posting your PLC code will make it easier and quicker to answer your problem.

[pszczepan 2]

It is NSJ...-G5D unit 3.0 OK - simply example 5 non-retain addresses and no internal addresess input area: output area: Why it needs 5 non-retain? Edited 18 Nov 2008 by pszczepan

[BITS N BYTES 66]

For each ladder FB instance a single NON-RETAIN is automatically assigned to FB memory. For each non-boolean variable an additional NON-RETAIN is assigned. You have one function block instance and four [uINT] variables = 5 NON-RETAIN assigned to FB memory. I don't quite understand why this concerns you? The whole purpose of Function Blocks is that where and how memory is assigned is completely unimportant/irrelevant. Shared FB memory [H memory areas]are shared/reused for each FB instance to save memory usage. Hope this helps.