PMAC Quick Reference Guide 6. If the vector method of locating the arc center is used, the vector is specified by its I, J, and K components (I specifies the component parallel to the X axis, J to the Y axis, and K to the Z axis). This vector can be specified as a distance from the starting point (i.e. incrementally), or from the XYZ origin (i.e. absolutely). The choice is made by specifying R in an ABS or INC statement (e.g. ABS (R) or INC (R) ). This affects I, J, and K specifiers together. ( ABS and INC without arguments affect all axes, but leave the vectors unchanged). The default is for incremental vector specification. 7.
PMAC’s convention is to take the short arc path if the R value is positive and the long arc path if R is negative: • If the value of R is positive, the arc to the move endpoint is the short route ( • If the value of R is negative, the arc to the move endpoint is the long route (>=180 degrees) 8. When performing a circular interpolation, the individual axes describe a position Vs time profile close to a sine and cosine shape. This is true also for their velocity and acceleration profiles. Therefore, circular interpolation makes an ideal feature to described trigonometric profiles.
Further, the period (and so frequency) of the sine or cosine waves can be set by the total move time given by TA+TM. close delete gather undefine all &1 #2->2000Y ;X is phantom open prog1 clear inc inc (r) ta300 ts0 tm1000 ;TA+TM is period i13=10 normal k-1 ;X-Y plane circle1 ;clockwise x0 y0 i10 ;complete circle close &1b1r Motion Programs 55