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Old December 11th, 2017, 01:40 PM   #14
Ken Roach
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Van, I don't think it's a functional issue. The I/O should still run fine, even though the address points to an alternate tag.

Glenn, thanks very much for the additional information. I think you've encountered an uncommon issue with an uncommon implementation.

My guess (and it's only a guess) is that this is an issue related to how stacked Aliases work, but with the extra twist of a special Module-defined datatype for the 1746 modules in the 1747-AENTR adapter.

The 16-point discrete input module datatype is actually 8 bytes long:

ConnectionStatus is a BOOL that takes up 4 bytes.
Data is an INT that takes up 2 bytes
Point_0 through Point_15 are BOOLs that take up 2 bytes.

The "Point_x" BOOL tags aren't a BOOL[16] array, but rather individual points. I think that's similar to how the discrete points are addressed in 5069 series I/O modules, but I have not worked with those yet.

So they aren't "overlays", but they aren't "really aliases" either.

The resolution of the issue might boil down to "use the BOOL tag addressing to avoid this upload database issue". It would be interesting to see what RA technical support makes of it.
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