What Table Occurrence does the current layout refer to? Given this reference: PCAS Data::ID, you should be on a layout that refers to "PCAS Data" in the Show Records From box in Layout Setup... for the current layout.
You may need to use Go TO Layout to switch to the appropriate layout, update the current layout to refer to PCAS Data or you may need to change that Set Variable step to refer to the correct Table Occurrence.
(Table Occurrences are the "boxes" found in Manage | Database | Relationships. They aren't the items listed in Manage | Database | Tables.)
Thanx I thought show layout would devert to just showing data on the screen.
This has got me over the first hurdle. On to the next one.