I’m running a Schedule in AVA, but something unexpected happens, e.g. the temperature suddenly drops. What could be the cause?

It’s probable that there is a very short step in your Schedule that is too small for you to see at your current zoom level.

Try zooming in on the Schedule (using the scroll bar at the bottom right of the AVA window) to see if there are any small steps (e.g. for a different temperature) that explain your observation.  You can also create the Rich Text Format report of your experiment file (see FAQs for further details) and review the recipe (which lists all steps in the Schedule, no matter now small) and the event log (what actually occurred in practice).

You may have accidentally inserted such tiny steps into the Schedule if you made quick changes manually in the Apparatus window while AVA was running in Schedule mode.  Any changes you make in Apparatus are recorded and then will be present when you run the Schedule next time, as part of AVA’s ‘track and repeat’ functionality.

However, note that while you can make instant changes in the Apparatus window, when experiments are later being played in the Schedule they can have end conditions as standard, which have to be fulfilled in order for AVA to move on to the next step.  For example, you may briefly change the circulator temperature setpoint in the Apparatus window and quickly change it back, but when the Schedule with new added temperature control step is replayed, its default settings will require that now AVA waits for the specified temperature to be achieved before the step moves on.

To prevent this issue:

  • Ensure all users are aware that making changes in the Apparatus window can change the Schedule in this way. When running a Schedule, they should avoid making changes in the Apparatus window.
  • Before you run an experiment, we advise that you generate the Rich Text Format report, and carefully review the recipe line by line to identify any steps that should not be there.
  • You can then go to the AVA Schedule window and delete/edit any incorrect steps.
  • Another suggestion would be to run the experiment in demo mode to check it before running it with actual chemistry.