Error handling is an important feature of both the core scheduler and the application interface.
Error handling aims to provide the user with the maximum possible amount of information on the nature of any error and also offer the possible options that can aid recovery with the least inconvenience.
When an error occurs, either during an operation such as device initialization or during schedule execution an error message will be added to the “Error Handler” tool window at the bottom of the main application.
The error icon will also change from grey to red to indicate that there is one or more active errors that require attention.
See the following screen shot for an example that shows the Error Handler window open and showing an error message that indicates that no labware objects are available in Store1.
The error is shown with a disabled OK button until the operator selects of the presented recovery actions.
Once an action is selected the OK button is enabled to allow the user to commit the required action.
The following recovery actions are generally available, depending on the nature of the error:
- Ignore – some errors can be ignored if the user deems this to be appropriate
- Retry – the scheduler will retry the failed operation. Before requesting this action the user should normally ensure that the source of the problem is resolved
- Abort schedule thread – this action will stop the current schedule thread and leave any labware objects that belong to the thread at their current location
- Abort schedule – as per “abort schedule thread” but this action will abort all schedule threads that are part of the schedule execution
Note that any schedule abortion may leave labware objects in the system and hence stop other schedule execution from continuing normally.
Manual intervention may be required to remove the labware objects and once this has been performed the scheduler will have to be informed of their removal to allow awaiting schedule threads to continue.
Clearing Handled Errors
After an error has been handled it will become “grayed out” and the flashing red icon will stop flashing.
Clicking on the circled button below will clear all handled errors from the error handling GUI and just leave any un-handled (pending) errors.
This is useful to clear the GUI after handling several errors. Note that the errors will not be deleted from the database and hence will be retained for future inspection if required. ( IE, they are simply removed from the GUI, not removed from the event database )