The migration from XactMeasure commands to geometric tolerance commands attempts to automatically select the appropriate feature math option, datum math option, tolerance zone math option, and standard:
If all of the considered feature commands use least squares math, then the feature math option is LSQ. If any of the considered feature commands use different math, then the feature math option is DEFAULT.
If all of the datum feature commands use least squares math, then the datum math option is LSQ. If any of the datum feature commands use different math, then the datum math option is DEFAULT.
The tolerance zone math option after migration is always DEFAULT.
In the XactMeasure dimension, if the "GD&T standard" was set to "Custom" instead of "ASME Y14.5" or "ISO 1101", then the migrated geometric tolerance command uses the ISO 1101 standard.
PC-DMIS migrates feature commands that don't have least squares datum math to the DEFAULT datum math. These include primary datum planes, secondary datum lines, tertiary datum points, and translated planes.
In some cases, you may not want to use the math types or standard PC-DMIS chooses during migration. You can control the migrated math options or the standard (ASME or ISO) to apply. To do this, create a file named fcfMigrationPreferences.json and place it in C:\ProgramData\Hexagon\PC-DMIS\2023.2\. Note that the C:\ProgramData\ folder is hidden by default.
The fcfMigrationPreferences.json file must be in the JSON format (see https://en.wikipedia.org/wiki/JSON).
Here is an example file:
{
"preferred considered feature math type": "least squares",
"preferred datum math type": "least squares",
"preferred tolerance zone math type": "least squares",
"custom standard migrates to": "ASME Y14.5",
"default standard migrates to": "ASME Y14.5"
}
When the fcfMigrationPreferences.json file does not exist (or exists but is not valid JSON), then PC-DMIS selects the migrated math options according to the feature command math options as described above. When the fcfMigrationPreferences.json file exists, and PC-DMIS determines that it is a valid JSON file, and it has valid keys and values for controlling the migration, then PC-DMIS uses the math options defined by the fcfMigrationPreferences.json file.
The valid keys for the fcfMigrationPreferences.json file are:
"preferred considered feature math type"
"preferred datum math type"
"preferred tolerance zone math type"
"custom standard migrates to"
"default standard migrates to"
Starting with PC-DMIS version 2023.2, you can't have different GD&T standards in a single measurement routine. If PC-DMIS detects that they are different, it overrides the “custom standard migrates to” setting with the “default standard migrates to” setting.
Invalid keys in the fcfMigrationPreferences.json file are allowed, but they are ignored. If the fcfMigrationPreferences.json file exists, and PC-DMIS determines that it is a valid JSON file, but that it lacks one of the valid keys, then the behavior for that key is the same as if there were no fcfMigrationPreferences.json file.
The valid values for the math type keys in the fcfMigrationPreferences.json file are:
"default"
"least squares"
"default with ISO constrained L2" (only valid for the preferred datum math type)
For any of the valid math type keys, if the value is "least squares", then the corresponding migrated math option is LSQ. For the "preferred datum math type" key, if the value is "default with ISO constrained L2", then the migrated datum math option is DEFAULT for ASME but is CL2 for ISO. For any of the valid math type keys, if the value is anything else, then the corresponding migrated math option is DEFAULT.
The valid values for the "custom standard migrates to" and "default standard migrates to" keys in the fcfMigrationPreferences.json file are:
"ASME Y14.5"
"ISO 1101"
If the "custom standard migrates to" key is in the fcfMigrationPreferences.json file, the "custom standard migrates to" and "default standard migrates to" keys must both have the same value.
If the value for the "custom standard migrates to" key differs from the "default standard migrates to" key, then the "default standard migrates to" key takes precedence.
If the "default standard migrates to" key is missing or is found to be invalid, PC-DMIS reads through the routine and counts the total number of ISO and ASME commands. The following "counting" logic controls which GD&T standard PC-DMIS uses for all migrated Size and Geometric Tolerance commands.
If the combined total of ISO Size and XactMeasure commands is greater than the combined total of ASME Size and XactMeasure commands, then all of the migrated Size and Geometric Tolerance commands use ISO 1101.
If the combined total of ISO Size and XactMeasure commands is less than the combined total of ASME Size and XactMeasure commands, then all of the migrated Size and Geometric Tolerance commands use ASME Y14.5.
If the combined total of ISO Size and XactMeasure commands is equal to the combined total of ASME Size and XactMeasure commands, then all of the migrated Size and Geometric Tolerance commands use the GDTStandard entry in the Dimensions section of the PC-DMIS Settings Editor. For details, see "GDTStandard" in the PC-DMIS Settings Editor documentation.
The "default standard migrates to" key only affects XactMeasure to Geometric Tolerance migration. Starting with PC-DMIS 2023.2, PC-DMIS handles the migration of older Geometric Tolerance commands automatically using the “counting” logic described above.
The valid keys and values in the fcfMigrationPreferences.json file must be in English.