Using Switches in Mastercam Post Processors

One of the great advantages about the Mastercam Post Processor is that it isn’t locked out to the user.  When you get a post from TriMech, or if you use one of the default posts, there are some settings you can modify to customize your Mastercam experience.

For this explanation, I’ll be using the Mastercam Editor that comes with your Mastercam install and is the default g-code editor when you start up.  The easiest way to find it is to post out some code. Once you’ve got your editor open, you can browse to any of your Mastercam posts to see some MP text highlighting. Note the use of collapsible #regions in the image below.

Mastercam code expert

Mastercam Editor

How to find your posts

The file you are looking to open is going to be the *.pst file and might be named something like ‘MPFAN.pst’, ‘MPPOSTABILITY_something_something.pst’ or something with the name of the machine and the controller, like ‘AVEREX_HS_FANUC.pst’.  Whatever the name, if it’s got .pst as the extension, it’s your post.

If you don’t use the Mastercam Editor, you can use CIMCO or even a generic text editor like Windows Notepad, but you won’t get the MP text highlighting, and regions won’t be collapsible/expandable for you.

Once you have your .pst file open there should be a Revision log at the top.  Like this (highlighted in blue below):

 revision log

Revision log

The hashtag (#) starts a comment line, so this section is all comments for us editors to review information about the post.

Screenshot of Mastercam code expert

The hashtag starts a comment line

Be sure to add your own line to the bottom of this section, starting with a hashtag (#) if you’re making any changes.  And be sure to include your initials! If you don’t see a revision log (posts starting with ‘MPPOSTABILITY’ might not), you should add a commented line like this if you make any changes.  This is the first place code editors look to see what has changed from the original version, no matter who made the change.

Mastercam Post Processor Switches

We want to look at using the built-in switches to help customize your post.  Each of the different post engines have different switches in the post. Also, different Machine types have different switches. We are focusing on CNC Mill posts for this article (Fanuc to be exact), but if you are using a different machine, your post will probably have switches too, so keep reading and see if you see something similar!

Now that we know we are in a generic post, let’s find the switch section.  In a generic, the switches are found in the “General output settings” region.

general output settings

Find the switches in the “General output settings” region

If you are not using a generic post, search the word “switch” and it should take you to a switch section that you can review and make changes.  Be sure to read the comments to see helpful information about each switch.

If you’re not sure or need help with any of your switches or if you have any other questions about your Mastercam post processors, reach out to us on support at Be sure to include a Zip2Go for us so we have all the files we need to help review your issues with you.

How to Create a Zip2Go in Mastercam

  1. In Mastercam click File in the top left-hand corner of the Mastercam screen.
  1. Click the Zip2Go
Save Zip2Go

Save Zip2Go

  1. Then click Create
Create Zip2Go

Create Zip2Go

  1. Click on the file types you want to include if you are not sure leave default, then click Next
Highlighted file types to include in Zip2Go

Highlighted file types to include in Zip2Go

  1. Then click Finish, it will ask you where on your PC to save the Zip2Go and we recommend the desktop.
  2. Then you can attach the .MCAM-CONTENT file to an email and send to a client success agent.

NOTE: if you are using a mix of generic post and custom posts, you might find switches in one that are not in the generic.  For example, the G92 vs G54 option is found under misc. values for the generic posts, not in a post switch!  In a generic post, to get G54, G55, etc., always have your Misc Int 1 = 2 in your toolpath.  Other non-generic posts might have it as a switch, so look for it there instead!

Aric Duprey

Aric Duprey is a Client Success Analyst with MACDAC Engineering / TriMech
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