Why prc add a ptpcommand of same positon of the first point of linecommand?

[lim_zhang]

why add a ptp command at first?who can explain that...thank you!

[Johannes @ Robots in Architecture]

Hello,

If you start with a LIN command you would go from the start position - which might be somewhere else - in a straight line to the first LIN, including the possibility of singularities etc.
Also, LIN movements do not contain any information regarding the posture of the robot. With a PTP movement the posture at the start of the robot toolpath is clearly defined, as will be all positions after that.
If you start with your own PTP movement, you won't get an extra PTP movement.

Hope that makes sense!
Best,
Johannes