Post Processor Editing Fix - Mastercam

Mastering the Art of Mastercam Post Processor Editing: From G-Code to Control

Debugging: The MP.DLL and MPMASTER

When your post crashes or outputs garbage G-code, use the MP.DLL Debugger:

1. In Mastercam, go to Settings > Control Definition > Post Processor.
2. Enable Debug and Log NCI.
3. Post your code. The debug window will show you exactly which line of the post logic is failing.

3.2 The Suffix System

• No Suffix (e.g., x): The variable itself (mathematical value).
• $ Suffix (e.g., x$): The output formatted string of the variable. This respects the decimal places and formatting defined in the System Parameters section (usually near the top of the .pst file).
  • Wrong: G00 X x (Outputs raw math, maybe too many decimals).
  • Right: G00 X x$ (Outputs formatted X100.000).

The Golden Rules of Sanity

1. Always work on a COPY. Never edit the original .pst. Save it as MyMachine_EDIT_2024.pst.
2. Test with Air. After editing, run the code with the tool 6 inches above the part. Watch the distance-to-go.
3. One change at a time. Don't fix coolant, arcs, and tool changes in one go. Validate each edit.
4. Beware of .PSB files. If you have a .psb with the same name as your .pst, editing the .pst may have zero effect because the binary overrides it.