# Reserved distance for time calculation (P-CHAN-00307)

P-CHAN-00307 | Time preview: Reserved distance for time calculation
Description | The time preview function allows the calculation of the time that the CNC needs to travel a certain distance, taking into consideration the current speed profile. This parameter specifies the distance. The calculated time is output on the PLC interface

The specified distance refers to the tool centre point path in the default setting but can be switched to the workpiece contour by P-CHAN-00340 .

The parameter value 0 deactivates the time preview.

Parameter | position_lookahead_distance
Data type | UNS32
Data range | 0 ... MAX(UNS32)
Dimension | 0.1µm
Default value | 0
Remarks |