Using Canadian National Transformation V1(NTv1) with AutoCAD Map 2012/2013

[norman.yuan]

We have recently moved up from Acad Map 2009 to 2012 and ran into issue with using NTv1 for NAD27<->NAD83 coordinate transformation.

Most our work uses NTv2, but we do have some projects that requires to use NTv1. With Map 2011 or older, it is simple to configure AutoCAD Map to use Canadian National Transformation grid file for coordinate transformation, either NTv2 or NTv1.

Since AutoCAD Map 2012, doing coordinate transformation between NAD27 and NAD83 based on NTv2 works OK, as previous AutoCAD version. However, if we configure AutoCAD Map to use NTv1, the conversion stops working, which can be evidented by using command "MAPTRACKCS" ("Track Coordinates" palette). We also has a custom developed tool that uses AutoCAD Map's platform API to do the coordinate trasformation and works in the similar way as the "Track Coordinates" palette. When using NTv1, our tool throws an exception, while using NTv2, everything is OK.

We also tried on AutoCAD Map 2013. The sameing: NTv2 works and NTv1 does not. Does anyone (Canadians, please!) use NTv1 with AutoCAD Map 2012/2013 successfully?