[error 5602]

I understand the problem now.

PPL_B gets its own copy of "Get Tag LUT.vi" when you compile the PPL.

Then when you call VI_A, it refers to the "Get Tag LUT.vi" in vi.lib.

They are not getting the same tag lookup table.

To avoid this, I think that you will need to build Get Tag LUT into its own PPL. Then have PPL_B and VI_A call that PPL instead of vi.lib.

This would requires some re-structuring of the Tag Engine library before building the shared PPL.

[error 5602]

Error 5602 is Tag not found.

[error 5602]

Is PPL_B in the same application context as VI_A?

Tags are stored in DVRs.