The display of cutter compensation codes (G41/42) appears to be reversed. When my program calls for G42, the display shows G41. Conversely, when my program calls for G41, the display shows G42. Can someone tell me if this has been fixed in a more recent version or if I should file a bug report for this?
I've been using comp for years, and have never noticed this. I just checked with 3.042.040, and it woks correctly. Perhaps what you're seeing is due to the next issue?
One other thing I noticed is more of an annoyance than a bug. In the active G code display, the state of the various modal G codes that are being displayed does not reflect the current line of code being executed. Instead, it displays the upcoming state based on the General Config value for Lookahead Lines. For example, if line 50 in my program contains a G42 and my Lookahead Lines value is 20, the display will change to show G42 (actually G41 because of the bug) when line 30 in the program is executed. I verified this by changing the Lookahead Lines value. I did find through testing that the Cutter diameter compensation is not actually activated until the code is executed, but it's somewhat misleading when the display is updated early.
This is because Mach3 is a buffered system. The code is always read in advanced and placed into a queue. I think the displayed code may be more accurate in Version 4, but for now, it is what it is.
I believe that reducing the lookahead will reduce performance in CV mode, especially with 3D work. I personally don't need Mach to tell me when I'm in G41/G42, so it's not a big deal to me.
One other setting that I'd like more information on is the Advanced Compensation Analysis setting under the Mill Options tab on the Ports and Pins screen. What exactly does it do? What would the reason be to NOT have it set?
I don't think there is a reason not to use it. I think when the advanced mode was added, the original was left in place. I'm pretty sure the original comp will gouge inside corners if they don't have a radius.