# Trial control in multiple arenas

Each arena gets its copy of Trial Control Settings

If your experimental setup includes two or more arenas, Trial Control is applied to each arena separately. This means that, if a condition is met in one arena, EthoVision XT takes the corresponding action in that arena, not the others.

EthoVision XT evaluates the instructions for each arena within the same sample time. The order in which arenas are evaluated is not stored in your data.

See also an example

▪Working with trial control in multiple arenas.

Using zones in multiple arenas

A condition or action is not specific to one arena. If the condition is based on a zone, that zone must be present in all arenas, and have the same name.

If the zone is not present in an arena, Trial Control cannot progress for that arena. Therefore, tracking does not stop unless you set a maximum trial duration or tracking reaches the end of the video. See Control the end of tracking

Maximum trial duration with multiple arenas

Note the difference:

▪If the Trial Control Settings include a maximum trial duration, tracking stops in all the arenas simultaneously.

▪If the Trial Control Settings does not have a maximum trial duration, and a condition is set before the Stop track box, tracking does not necessarily stop in all the arenas simultaneously. Consider the following example:

Start tracking is set when the subject is found for the first time, just like in the default Start-Stop trial rule. A Time condition of 5 minutes is placed before the Stop track box. If the subjects in two arenas are found for the first time at different times, tracking starts at different times in the two arenas. Tracking also stops at different times, after the five minutes applied to each subject independently.