Is the design file format different in PI Expert v.6.6?
No, PI Expert v.6.6 has the same file format as version 6.5. PI Expert v.6.6 uses the *.UDS file format. The *UDX and *.UDF formats were used with previous versions, prior to 5.0 and 6.1, and must be converted to work with PI Expert v.6.6. This conversion may slightly modify the original *.UDX, *.UDF file results. The PI Viewer is available to review the original content of *.UDX, *.UDF files.