Motion stop

Look into interrupts inside expert programming part of the manual. Inside your interrupt you will need BRAKE and at the end- RESUME.

BRAKE, not BREAK. But, aside from that, Mentat is correct.

You want to pay special attention to the program structure -- when the RESUME command is used, the program pointer jumps to the stack level where the Interrupt was declared. This will drive your subroutine -- usually I use a three-level stack: the "main" routine where the Interrupt is declared, and which calls a motion subroutine which contains just the INTERRUPT ON command, and calls the motion routine which contains just the INTERRUPT ON command, and the motion from A to B, and the Interrupt Service Routine (ISR), which the Interrupt calls. Inside the ISR, BRAKE halts the robot motion, but the RESUME command (which is badly named) is what cancels the active motion -- without the RESUME command, the robot will simply resume the interrupted motion where it left off. If the RESUME command is executed (RESUME is only allowed inside ISRs), the program pointer will jump back to the main routine, one line after the call to the motion routine. This happens even regardless of how deep the calling stack is, which is why it's so important to be careful at what level you declare the Interrupt, and at what level you use it.

The "motion" routine also needs to end with some command to break the Advance Run Pointer, like a WAIT FOR TRUE. Otherwise, the ARP can get back to the Main routine before the Interrupt is triggered, which will cause errors. This does mean that you can't end an interruptable routine with a smooth approximated "flow" into the next move, which is another constraint to keep in mind.

VERY bare-bones example.

DEF MAIN
  INTERRUPT DECL 10 WHEN IN[1] DO ISR() ; declare interrupt
  PTP P1 ; start position for search motion
  SearchMotion()
  INTERRUPT OFF 10 ; in case ISR was never called.
  ; RESUME command will jump the program pointer back to this line, cancelling any pending motions in SearchMotion()
  IF $OUT[1] THEN
    ; ISR was called
  ELSE
    ; ISR was never called, robot reached P2 without $IN[1] ever going true
  ENDIF
END

DEF SearchMotion
  INTERRUPT ON 10 ; arm interrupt.  ISR will be called on the rising edge of $IN[1]
  $OUT[1] = False ; indicator that ISR was called
  LIN P2 ; search motion to be interrupted
  WAIT FOR TRUE ; break advance run pointer.  Without this, the advance run pointer can get back to Main before the Interrupt triggers, and cause a fault
END

DEF ISR()
; Interrupt Service Routine
INTERRUPT OFF 10 ; protect against double-triggering
BRAKE ; stop active motion
$OUT[1] = TRUE ; indicate that ISR was called
RESUME ; cancel all pending motion, jump main run pointer back to Main()
END

please add in main program, directly after SearchMotion()

INTERRUPT OFF 10

this ensures that interrupt is no longer active. failure to do so will lead to surprises when you add more things into program such as motions and other subprogram calls after search.

Yes, Panic is correct. Also, the ISR should start with an INTERRUPT OFF 10, to protect against double-triggering. I've edited my code to reflect that.