Reference Manual

Turbo PMAC/PMAC2 Software Reference

Turbo PMAC On-line Command Specification 292

This command causes all closed-loop motors defined in the addressed coordinate system to begin

immediately to decelerate to a stop, aborting the currently running motion program (if any). It also brings

any open-loop enabled motors in the coordinate system to an enabled zero-velocity closed-loop state at

the present position. If global I-variable I36 is set to 0, it will also enable any disabled motors in the

coordinate system, bringing them to a zero-velocity closed-loop state at the present position. However if

I36 is set to 1, it will have no effect on disabled motors; the E command should be used for these instead.

Each closed-loop motor in the coordinate system will decelerate from its present command velocity to

zero velocity at a rate defined by its own motor I-variable Ixx15. Note that a multi-axis system may not

stay on its programmed path during this deceleration. If the time-base (override) value for the coordinate

system is exactly 0% when the A command is given, the motor will abort at the present position even if

the command velocity is not zero; otherwise a ramp-down trajectory will be computed using Ixx15 and

executed using the override value.

An A (abort) stop to a program is not meant to be recovered from gracefully, because the axes will in

general not stop at a programmed point. An on-line J= command may be issued to each motor to cause it

to move to the end point that was programmed when the abort occurred. Then the program(s) can be

resumed with an R (run) command.

To stop a motion sequence in a manner that can be recovered from easily, use instead the Quit (Q or

<CTRL-Q>), the Hold (H or <CTRL-O>), the Quick Stop (\) or the Halt (/) commands.

Example

B1R .................. ; Start Motion Program 1

A ...................... ; Abort the program

#1J=#2J= ...... ; Jog motors to original move-end position

R ...................... ; Resume program with next move