Parameter 56 Inverse time Setting for all files

[louielc]

A little background - I am new to 4th axis and had an issue with the speed of my engraving using the 4th axis. I realized it was due to the program i used not adding the speed for the A axis in degrees/min separately and was able to get it to work by adding G93 to my file and using Inverse Time by setting Parameter 56 to 8 in CNC12. My question is, can i leave parameter 56 as 8 all the time, even when im not using the 4th axis and just doing a regular x,y,z job. Or do i have to change it back and forth every time? Is the system smart enough to know just to use regular federates if there is no G93 in the file?

[louielc]

Okay so I testing this definitely needs to be changed back for a regular file to 4 which is the default value or it affects the cut. Just in case anyone else sees the issue. Now I just need to figure out if I can have a macro change it and if it requires a system reboot to take effect. If anyone knows that please let me know.

[tblough]

During your experiments, did you issue a G94 to cancel inverse time mode? G93 is modal and will stay in effect until cancelled. Bit 3 of parameter 56 only affects how G93 intreprets the feedrate as either feed per minute or feed per second - effectively multiplying the feedrates 60X. It should not have any affect when not in inverse feedrate mode.

P56 = 4 Turns on a percentage bar under the feedrate display, and inverse time moves are in feed per minute. P56 = 8 turns off the percentage display and sets inverse time feedrates to feed per second (60X increase). You need to review the parameter section of the manual on how bitwise parameters work.

[louielc]

Thanks that the direction , i read the manual but am new to this type of control. So i wasnt sure if G94 would cancel just for the file, or in general. Ill do more testing but thanks for the insight. That should get me on the way.