The Help in Studio 5000 would appear to indicate that the VIS setting can only be changed for AOI instances when using FBD. Contr_Conn mentioned this a bit earlier in the thread. And yes, some of Rockwell's built-in blocks do allow this in Ladder. The Scale instruction was mentioned earlier, but that is an FBD instruction and pretty much all FBDs allow this. The AOI version they offer on their download site doesn't allow that same configurability when in ladder.
Determines whether the parameter is visible on the Ladder Diagram and Function Block Diagram instructions when the Add-On Instruction is called. Right-click the Vis heading to select or deselect all the rows in the column.
If Req is selected, Vis is selected and read-only. The Visible function is not applicable for members of InOut parameters.
If the parameter is not required, the Visible configuration may be overridden for Add-On Instruction called in Function Block Diagrams routines. Overriding the visibility at the instruction call level does not affect the definition configuration.
OG