Asynchronously Raised Errors - ABB MultiMove Applications Manual

7.3 Asynchronously raised errors

What is an asynchronously raised error
Asynchronously raised errors can be raised by another instruction than the
instruction where the program pointer is. This means that an asynchronous error
can be raised while the robot is in the middle of a path movement. For more
information about asynchronously raised errors, see Technical reference manual
manual - RAPID kernel.
The technique with asynchronously raised errors allows a failing instruction in one
task program to raise an error in all other task programs with synchronized
movements.
How to raise an asynchronous error
The instruction ProcerrRecovery will raise the error ERR_PATH_STOP and stop
the movement for all task programs with synchronized movements.
Asynchronous errors can also be raised by process instructions (e.g. ArcL). These
can raise one error code (describing the cause of the error) in the task program
where the error occurred, and raise the error ERR_PATH_STOP in the other task
programs with synchronized movements.
The task programs without errors
If two task programs run synchronized move instructions and one of them raise
an asynchronous error, the movements will stop for both tasks. The task program
where nothing went wrong will then get the error ERR_PATH_STOP. This error must
be handled by an error handler. The error handler can handle ERR_PATH_STOP by
just waiting for the other task to solve its problems and then resume the movements.
By using the instruction StartMoveRetry, the execution will continue when all
tasks reach this instruction.
Independent movements in the error handler
If the error handler in one task program needs to execute a move instruction, the
synchronization must be suspended first.
The synchronization is automatically suspended by the StorePath instruction.
All tasks with synchronized movements must execute a StorePath instruction
before the synchronization is turned off and the execution can continue.
The instruction RestoPath will restore synchronization to the mode it had before
StorePath. All task programs with synchronized movements must execute the
RestoPath instruction in their error handlers before the synchronization is resumed
and the execution can continue.
Between the instructions StorePath and RestoPath, the failing task program
can move independently to solve its problem. Since RestoPath works as a
synchronization point, the other task programs will wait at this point until the
problem has been resolved.
If the task program is not in synchronized movements mode, StorePath and
RestoPath act just like they do in a single robot system. This means that the same
Application manual - MultiMove
3HAC050961-001 Revision: E
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7 RAPID error recovery
7.3 Asynchronously raised errors
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