The XPDL command lets you easily replace the indicated extension line of a dimension with a real Line entity that can be trimmed or broken into parts. It is used when you need to trim or to make a break on a dimension by its extension line so as to escape it from other drawing entities that intersect with it.
To make a trimming or breaking on the extension line of a dimension entity, most people would instantly explode the dimension into elementary entities first and then do the editing thereafter. However, this is not the recommended way, because it is too wasteful in terms of drawing resource. The exploded result can never be a dimensioning again to TwinCAD or to any other applications that read it.
In fact, if you are going to make the extension line shorter, you may apply the QCHANGE command directly. If you are going to separate the extension line into parts, you may turn it off via the SETDIM command, create an ordinary line entity as a replacement via the LINE command, and then do the required editing thereafter. The dimension entity is thus retained and only one additional line entities is created. And, that is what XPDL does for you.
As most of the purpose of this kind of editing is to escape the extension line from some other entities at certain points by making breaks of it, the XPDL will also create the breaks for you if you require.
XPDL will prompt the following sequence:
You are asked to select a linear or an angular dimension by one of its extension lines. It is the extension line nearest to the pick point be replaced by the real line entity. In fact, you may also select an existing line which is to break for the same escaping purpose.
After the extension line is replaced by a line, or an existing line is selected, the next prompt asks you to designate a point on the line to break. XPDL will issue the INTersection snap directive automatically for you to help designating the break point, assuming you are to escape the line from other intersecting objects. You may press space bar to skip this breaking operation or issue other snap directive to snap a point other than intersection point.
If a break point is given, the line will be broken into two parts with a gap in between around it. The distance of this gap is determined by the system variable @DIMGAP.
XPDL will cycle through the same prompt sequence until you press the space bar to the first prompt (selecting nothing) or pressing <Ctrl/C> to terminate the operation.
The XPDL command is an external command provided by the TCL program file "XPDL.TCL" or "XPDL.TCA". Either file must be present in the COMMANDS sub-directory where the TwinCAD resides. If you can not issue XPDL command, you may solve the problem by copying the "XPDL.TCL" to the COMMANDS sub-directory.