8. “Special Case” Tactics & Notes This section of the manual covers some tactics that you can use to achieve NC code output to match some special cases that we've come across over the years. This section is by no means an exhaustive reference of all the things you can achieve, because the only limits are your imagination. This section is meant to help stimulate your imagination by giving a few examples of how we've used some of the formatting “tools” in the GS post to overcome some specific formatting problems.
8.1 Concerning incremental / absolute output and the [IncMode] variable The [IncMode] variable gives you a great deal of control over how the absolute/incremental codes are placed in your NC programs. Instead of “hard coding” a G90 or G91 in any sequence, you can use G[IncMode] . The difference is that when the tool motion file that comes from the CAM program designates which parts of the tool motion are to be coded in incremental or absolute mode, PostHaste automatically places the corresponding G code in the location you've specified with G[IncMode]. For the [IncMode] variable to work, the following line MUST be present in the template: Inc/Abs G 91 90
( Inc first, then Abs. )
If you don't have it, PostHaste will warn you to add it before it will process the tool motion. You can use [IncMode] in any sequence. Here are 2 examples: ToolChange T[Tool] M6 G0 G[IncMode] X[H] Y[V] S[Speed] M[Direct] G[43] Z[D] H[LComp] End Sub O[Sub] G[IncMode] end
[----IncMode established at each tool change...
[----IncMode established at each sub.
Note: A G90 or G91 (according to the Inc/Abs line as formatted above) will automatically appear in the NC code whenever the mode is changed by information coming in from the tool motion file. This will NOT happen if the [IncMode] variable is used as the “trigger” variable for an UPON sequence - because the post expects you to have formatted your UPON sequence to handle it properly.