User's Manual

Turbo PMAC User Manual
318 Writing and Executing Motion Programs
The \ command is the best command to use to stop interactively within lookahead operation with the
intention of resuming operation. Any synchronous M-variable assignments set to happen within the
deceleration will execute.
Motors may be jogged away from this stop point, if desired. Also, motion can be reversed along the path
with the < command (see Reversal, below).
Normal programmed motion can be resumed with the > resume-forward, R run, or S single-step
command, provided all motors are commanded to be at the same position at which they originally stopped
with the / command. If any motors have been jogged away from this point, they must first be returned
with the J= command. Acceleration limits are observed during the ramp up from a stop here. The >
resume command puts the coordinate system in either continuous run mode, or single-step mode,
whichever mode it was in before the quick-stop.
End-Block Stop
The / end block command will stop motion at the end point of the move currently being added to the
lookahead buffer, even if the next move has already been calculated. Motion segments up to the end of
this move are still added to the lookahead buffer, and all segments and synchronous M-variable
assignments in the lookahead buffer are completed.
Motion will come to a controlled stop at the end of the latest move block being added to the lookahead
buffer without violating constraints. However, there can be a significant delay – over (Isx20*Isx13) msec
if the lookahead buffer is full – from the time the / command is given and the time the axes stop.
Motors may be jogged away from this stop point, if desired. Motion can be resumed with the R or S
command, provided all motors are commanded to be at the same position at which they originally stopped
with the / command. If any motors have been jogged away from this stopped point, they must first be
returned with the J= command.
Quit/Step
The Q quit command simply tells the motion program not to calculate any further motion program blocks.
(The S single-step command will do the same thing if given while the program is running.) Motion
segments up to the end of the latest calculated motion program move block are still added to the
lookahead buffer, and all segments and synchronous M-variable assignments in the lookahead buffer are
completed.
Motion will come to a controlled stop at the end of the latest calculated move block without violating
constraints. However, there can be a significant delay – over (Isx20*Isx13) msec if the lookahead buffer
is full – from the time the Q or S command is given and the time the axes stop.
Motors may be jogged away from this stop point, if desired. Motion can be resumed with the R or S
command. Motors do not have to be at the same position at which they were originally stopped with the
Q or S command. However, if it is desired to return them to this position, the J= command should be
used.
Feed Hold
The H feed hold command brings the feedrate override value to zero, starting immediately, and ramping
down at a rate controlled by coordinate system variable Isx95. Motion continues along the programmed
path to a controlled stop, which is not necessarily at a programmed point (and probably will not be).
Acceleration limits are not necessarily observed during the ramp down to a stop. Any synchronous M-
variable assignments set to happen within the deceleration will execute.
Motors may be jogged away from this stop point, if desired. Programmed motion can be resumed with
the R or S command, provided all motors are commanded to be at the same position at which they
originally stopped with the H command. If any motors have been jogged away from this stopped point,
they must first be returned with the J= command. Acceleration limits are not necessarily observed during
the ramp up from a stop here.