Reference Manual

Turbo PMAC/PMAC2 Software Reference
Turbo PMAC Global I-Variables 187
in-position settling and added dwell, until the commanded outgoing move starts, the coordinate-system
status bit “sharp corner stop” (Y:$002x40 bit 6) will be set.
If the cosine of the change in directed angle at a corner is greater than Isx85 (a small change in directed
angle; a gradual corner), Turbo PMAC will not automatically add a dwell.
The operation of Isx85 is independent of the operation of the similar function of Isx99, which controls for
outside corners in 2D cutter-radius compensation whether an arc move will be added based on the change
in directed angle. Isx85 works regardless of whether cutter-radius compensation is active or not, or
whether the corner is an inside or outside corner when cutter-radius compensation is active. If this is an
outside-compensated corner with an added arc, the corner angle is based on the moves without the added
arc (i.e. the uncompensated moves).
Example
If it is desired that motion in Coordinate System 1 be stopped if the change in directed angle is greater
than 45
o
(included angle less than 135
o
), then I5185 should be set to 0.707, because cos

= cos 45
o
= 0.707.
Isx86 Coordinate System x Alternate Feedrate
Range: non-negative floating point
Units: (user position units) / (Isx90 feedrate time units)
Default: 0.0
Isx86 can control the speed of motion for a feedrate-specified move when the motion of non-feedrate axes
is predominant. It is only used if the coordinate system is in segmentation mode (i.e. Isx13 > 0).
Feedrate, or vector-feedrate axes are those specified by the FRAX command; X, Y, and Z are the feedrate
axes by default.
If Isx86 is greater than 0, PMAC compares the move time for the vector feedrate axes, computed as the
vector distance of the feedrate axes divided by the specified feedrate (the F value in the program or Ix89),
to the move time for the non-feedrate axes, computed as the longest distance for these axes divided by
Isx86. It then uses the longer of these two times as the move time for all axes, feedrate and non-feedrate.
If Isx86 is 0, and PMAC sees a feedrate-specified move in which the vector distance is zero (i.e. no
motion of the vector feedrate axes), PMAC computes the move time as the longest distance of the non-
feedrate axes on the line divided by the program feedrate.
Isx86 has two main uses. First, it automatically controls the motion of non-feedrate axes when they are
commanded alone on a line in feedrate mode. Typically, these are rotary axes in a combined linear/rotary
system where only the linear axes are vector feedrate axes.
Second, it permits a fast dry-run mode in which the programmed feedrates are ignored. If no axes in the
coordinate system are vector feedrate axes (implemented with the NOFRAX command), then Isx86 will be
used for all moves, regardless of the F values in the program.
Example:
I5113=10 ; 10 ms segmentation period
I5190=1000 ; Speeds are specified as per-second
I5186=5 ; Alternate feedrate of 5 user units per second
INC ; Moves specified by distance
X20 F10 C1 ; Move time = 20 units / 10 (units/sec) = 2 sec
X10 C30 ; Move time = 30 units / 5 (units/sec) = 6 sec
C20 ; Move time = 20 units / 5 (units/sec) = 4 sec
See Also:
I-variables Isx89, Isx98, Isx13