Recovering from deadlocks

About deadlocks

A deadlock is an error that occurs when the number of locations available in the system is less than the number of microplates in the system. Because the microplates cannot move to the expected locations, the protocol either aborts or pauses, depending on the Deadlock behavior selection in the Tools > Options dialog box.

About the System State Editor

In the Tools > Options dialog box, if the Deadlock behavior is Show the System State Editor, the run will pause when a deadlock error occurs.

 

During the pause:

•	Systems with an Automation Control Unit. The Scheduler Paused dialog box appears. To access the System State Editor, click Bypass interlock, and then click System State Editor in the Bypass Interlock dialog box.

•	Systems that do not have an Automation Control Unit. The System State Editor dialog box appears.

In the System State Editor dialog box, you can:

1

View the status of the devices and locations to assess and correct the causes of the errors. For example, if the device status indicates that a labware at a particular location is causing device problems, you can physically remove that labware from the system and restore the device to its operational state.

2	Specify in the software that a labware has been removed from certain locations or from the system. For example, after you physically remove the labware that is causing problems, you need to indicate in the software that the labware is removed and its location is now ready to accept new labware.

3	Edit or reset the status of devices and locations. If you fixed a device problem, you can indicate that the device is now operational and ready to accept labware.

4	Continue the protocol run.

If you determine that the causes of the deadlock error cannot be fixed, you can choose to abort the run or allow the existing labware to finish processing but not introduce new labware. For more information about these options, see Pausing the run.

You can also open the System State Editor when you pause all runs. For instructions, see Pausing the run.

Viewing the device and location status

To view the device and location status:

1	In the System State Editor dialog box, click the Paused Status tab.

2	Review the information in the Paused Status tab.

The Paused Status tab contains the following information:

•	Causes of the deadlock error

•	Current locations of the labware in the system and the expected locations when the deadlock error occurred

•	The current status of all the devices and locations in the system

Note: The information in the Paused Status tab can be appended to the Main Log file. To do this, select Tools > Get Status.

 

Moving or removing labware from locations

The Plate Location Editor tab lists:

•	All active process plates in all running protocols

•	The current locations of the process plates

IMPORTANT The list does not include finished process plates. To see the finished process plates, click the Location Status Editor tab.

IMPORTANT You can move labware to any location except into a Labware Stacker.

To indicate that labware is moved or removed from locations:

1	In the System State Editor dialog box, click the Plate Location Editor tab.

2	To change the location of a process plate, select the new location from the list. If you want to indicate that a process plate was removed from the system, select REMOVE FROM SYSTEM.

Note: The software prevents you from selecting one location for two different process plates. If you select a location that is already occupied by another process plate, the software will exchange the two locations.

 

Editing the status of the devices and locations

 

CAUTION Do not change the status of device locations without fully knowing the state of all process plates and device locations. An arbitrary change can cause crashes when you resume the run. If you are uncertain of the state of the process plates and device locations, contact Automation Solutions Technical Support.

The Location Status Editor tab displays all labware in running protocols in:

•	The list of every device and associated locations

•	The status of the locations

Finished process plates appear in this tab. You can use the selections in this tab to remove finished process plates.

 

CAUTION Make sure finished process plates will not be used by downstream processes before removing them. Except to remove finished process plates, you do not need to change the status of device locations. The changes you made in the Plate Location Editor tab are automatically reflected in the Location Status Editor tab. For example, if you removed a process plate from a location in the Plate Location Editor tab, the status of that location will change from Plate available for pickup (location is occupied) to Ready for use (location is available for use).

To remove a finished process plate:

1	In the System State Editor dialog box, click the Location Status Editor tab.

2	Find the finished process plate location, and then select the new status from the list.

 

 

Status	Description
Plate available for pickup	Retains the finished process plate in the system.
Ready for use	Removes the finished process plate from the system.

Continuing the protocol run

After you specify the labware movement or removal and the new device and location status:

1	In the System State Editor dialog box, click Accept all changes.

2	Systems with an Automation Control Unit. In the Bypass Interlock dialog box, click Resume Run.

3	In the Scheduler Paused dialog box, click Continue to resume the run.

The Scheduler Paused dialog box also provides other options. For details, see Pausing the run.

Related information

 

For information about...	See...
Pausing a run	Pausing the run
Monitoring a run	Tracking the run progress of instances or devices
Viewing logs	Viewing logs
Tracking the run progress of instances, processes, or devices	Tracking the run progress of instances or devices
Contacting Agilent Technologies and reporting problems	Reporting problems