Reference Manual

PMAC 2 Software Reference
PMAC I-Variable Specification 121
Note:
Make sure that the specified acceleration time (Ix87 or 2*Ix88) is
greater than zero, even if you are planning to rely on the maximum
acceleration rate parameters. A specified acceleration time of zero
will cause a divide-by-zero error. The minimum specified time
should be Ix87=1, Ix88=0.
See Also
Acceleration Limits (Making Your Application Safe)
I-variables I13, Ix17, Ix88
Program Commands TA, TS
Ix88 Coordinate System x Default Program S-Curve Time
Range
0 .. 8,388,607
Units
msec
Default
50
Remarks
Ix88 set the default time in each half of the S in S-curve acceleration for programmed
blended LINEAR and CIRCLE mode moves in Coordinate System x. It does not affect
SPLINE, PVT, or RAPID mode moves. The first use of a TS statement in a program
overrides this value.
Note:
Even though this parameter makes is possible not to specify
acceleration time in the motion program, you are strongly
encouraged to use TS in the program and not rely on this parameter,
unless you must keep to a syntax standard that does not support this
(e.g. RS-274 G-Codes ). Specifying acceleration time in the
program along with speed and move modes makes it much easier
for later debugging.
If Ix88 is zero, the acceleration is constant throughout the Ix87 time and the velocity
profile is trapezoidal. If Ix88 is greater than zero, the acceleration will start at zero and
linearly increase through Ix88 time, then stay constant (for time TC) until Ix87-Ix88 time,
and linearly decrease to zero at Ix87 time (that is Ix87=2*Ix88 - TC). If Ix88 is equal to
Ix87/2, the entire acceleration will be spec in S-curve form (Ix88 values greater than
Ix87/2 override the Ix87 value; total acceleration time will be 2*Ix88).
Note:
The acceleration time will be extended automatically when any
motor in the coordinate system is asked to exceed its maximum
acceleration rate (Ix17) for a programmed LINEAR-mode move
with I13=0 (no move segmentation).
Make sure the specified acceleration time (TA or 2*TS) is greater
than zero, even if you are planning to rely on the maximum
acceleration rate parameters (Ix17). A specified acceleration time
of zero will cause a divide-by-zero error. The minimum specified
time should be TA1 TS0.
See Also
Acceleration Limits (Making Your Application Safe)
I-variables I13, Ix17, Ix87
Program Commands TA, TS