Option File Generator HelpINV Time Mode
Enter the prep code that establishes inverse time mode for this machine (usually 93). If this machine has only inverse time feed available, enter NA (not available) for both the UPM and UPR preparatory code. Regardless of the modes available, the postprocessor accepts FEDRAT commands with UPM and UPR modifiers.
For any GOTO/cmd that causes linear and rotary motion, the GPost can output inverse time feedrate (G93 F-inv) automatically by this flag. In addition, if the GOTO/cmd causes only rotary motion, then you can also select inverse time, units per minute, or degrees per minute as required.
Machines that are both Inch/Metric and UPM/UPR switchable often have different feedrate register formats for each combination. Clicking this button will activate the Register Format Dialog box that will provide the user an opportunity to set the feedrate register format for the mode under which it was activated.
This feature will output the radius of rotation used by some controllers to adjust the feed rates. Some MAHO 5 axis machines use A40 radius – C40 radius to update the feed rates.
Machines that are both Inch/Metric and UPM/UPR switchable often have different feedrate limitations for each combination. Enter the minimum feedrate allowable in the mode represented on this panel. These limits may result in different velocities, depending on the mode combination.
Machines that are both Inch/Metric and UPM/UPR switchable often have different feedrate limitations for each combination. Enter the maximum feedrate allowable in the mode represented on this panel. These limits may result in different velocities, depending on the mode combination.
Some controllers require that feedrates be scaled, such as inverse time in minutes. Enter a value to multiply the calculated feedrate by, for the mode represented on this panel.
For inverse time feed mode the postprocessor uses the FEDRAT command currently in effect and the distance it calculates for the next move in the formula VELOCITY/DST (where velocity is feed in UPM even if input is in UPR mode). For someone very short moves can cause conditions where the inverse time value calculated exceeds the machines ability to make the motion at this calculated feedrate even though the calculated value falls within the maximum values specified on this panel. To limit the maximum inverse time value calculated for short moves, enter the minimum time value that is to be used by the postprocessor for the calculation in either minutes or seconds as required. Any moves that would be made in less than the time value specified would substitute the specified time in the calculation.
When Auto is selected, the GPost will find the minimum time for each axis and compare the min-max feedrate settings and adjust the programmed feedrate automatically. When Disable is selected, the time value is 0.
Checking this box will set the postprocessor option that will identify any inverse time feedrate calculations the postprocessor was required to override due to the time for the move falling below the minimum time specified on this panel.
Note: it is necessary to verify the setting of the "maximum feedrate" of the rotary axes setting in DPM (degrees per minute) in the Machine Tool Type "Primary Axis" panel (applies to Dblcoms 123 to 125) for ABC axes. If this value is not set correctly, then the GPost can not adjust the feedrate properly under for inverse time mode correction option.
Some controllers require that circular move calculations for inverse time be made using the circle radius, where others require that the actual arc length be used. Choose the method appropriate for your machine's controller. Equivalent postprocessor commands:
PLABEL/OPTION,33,TO,0 $$ Use arc length (default).
PLABEL/OPTION,33,TO,1 $$ Use circle radius.
This field provides the option to cause the postprocessor to calculate the inverse time feedrate using one of two methods for MULTAX moves only. These values for non MULTAX moves can be resolved mathematically.
The iterative method is the default and is usually the most accurate. It will cause the postprocessor to calculate the distance of the move based on the points from the input file.
The analytical method uses the rtheta method. The postprocessor will attempt to calculate the tool tip distance from the center of rotation and the approximate angular displacement of the move.
Equivalent postprocessor commands:
PLABEL/OPTION,48,TO,0 $$ Use iterative method (default)
PLABEL/OPTION,48,TO,1 $$ Use analytical method
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