Rules

General rules

• The reserved words <X-COORD> and <Y-COORD> are the assigned values of the first path point, and must appear in all program formats to provide the first positioning move to the start of the path.
• It is mandatory that the reserved word <Z-COORD> be used for the Segment Start program format. It is calculated as the largest Z Rapid value of the current and previous segments, thereby allowing for the tool to be retracted from the part to a safe plane.
• Use of the <Z-COORD> reserved word is optional for the Program Start and Tool Change program formats. It is calculated in the following manner:

  <Z-COORD> = TL CHG (Z)

  Note: TL CHG (Z) is programmed in FeatureCAM.
• Whether <Z-COORD> is used or not, Post assumes that the tool is at this Z level, after the code for any of the aforementioned formats is generated.

Incremental programming rules

Warning: These are the rules for building post processors for controls that only support incremental input.

• Each occurrence of the following reserved words must be in the specified form in the program formats.

  Reserved word	Form
  <X-CHANGE>	<@X-CHANGE>
  <Y-CHANGE>	<@Y-CHANGE>
  <X-COORD>	<@X-COORD>
  <Y-COORD>	<@Y-COORD>
  <Z-COORD>	<@Z-COORD>

• The Program Start format may not contain any of the following reserved words: <@X-CHANGE>, <@Y-CHANGE>, or <@Z-COORD>. This is assuming that the first tool has been positioned at the start point (the first segment's tool change position) by the operator before starting the NC part program.
• The Program End format must contain the reserved words <@X-CHANGE> and <@Y-CHANGE> to reposition the tool back to the start point.