Knowledge Base

Start and Stop the Trial at Specific Clock Times

Aim

To control the start and stop of the trials, without the need for the researchers/technicians to be in the stable to control EthoVision XT.

Procedure 1 - One Trial

You want to start tracking at 9 AM (9:00) and stop at 7 PM (19:00). You are in the lab the day before.

1. Open the Trial Control Settings and create time conditions as in the figure below.
2. Before leaving the lab, in the Acquisition screen click Start Trial. The screen says Checking start condition.
3. The software waits until 9 AM on the following day and then starts tracking.
4. Tracking stops on 19:00 (7 PM).

Note: If you click Start Trial before 9:00, it will start tracking on the same day.

Procedure 2 - Repeated Trials Using a Series of Trials

You plan to record your subjects for 20 days. Each trial should be carried out during the day, from 8 AM (8:00) to 7 PM (19:00).

1. Create a Trial List with the number of planned trials. See Plan Your Trials.
2. In the Trial Control Settings, create a Start-Stop rule similar to the one above, to start tracking from 8 AM to 7 PM.
3. In the Acquisition screen, select Track all planned trials. In the Inter-trial interval field, enter the time that covers the interval from the end of one trial to some time before the beginning of the next. In this case the inter-trial interval runs from 7 PM to 7:59 AM = 12 h 59 min. Leave some time between the end of the inter-trial interval (7:59 AM) and the Time condition of the rule (8 AM). This way the two instructions will not interfere with each other. At 7:59 AM of the next day, the trial starts but the software waits till 8:00 AM to start tracking.
4. To start the first trial in the series, make sure to click the Start Trial button before the time specified in the Time Condition box placed at the left of the Start track box (in this case 8 AM).
5. In the remaining days you do not have to be in the lab at that time because the series of trials will do the work for you.

See also Acquire a Series of Trials (Batch Acquisition).

Procedure 3 - Repeated Trials Using Task Scheduler

You plan to record your subjects for 20 days. Each trial should be carried out during the day, from 8 AM (8:00) to 7 PM (19:00). This is an alternative method that makes use of the Windows Task Scheduler.

• Create batch files to trigger the start of the trials (this replaces the clicking of the Start Trial buttons in the procedures above).
• Use the Windows Task Scheduler to trigger the batch files at a specific time.
• Do not forget to add the planned trials in the Trial List; in this example, 20 trials.

Do the following:

1. Using the Windows Notepad, create a file with extension VBS that performs a key press Ctrl+F5. This triggers the start of the trial. Enter the following code:
   
   Set WshShell = WScript.CreateObject("WScript.Shell")
   WshShell.AppActivate "EthoVision"
   WScript.Sleep 1000
   WshShell.SendKeys "^{F5}"
   
   And name this file vbsprogram.vbs.
   
   Note: The WScript.Sleep 1000 (1 s delay) ensures that the key press is given when EthoVision XT is in focus.
2. Using the Windows Notepad, create a second file, this time with extension BAT, which triggers the vbs script. Enter the following code:
   
   wscript "C:\vbsprogram.vbs"
   
   And name this file start_vbsprogram.bat.
3. Save both files on C:\.
4. Start the Windows Scheduler and define a new basic task, which runs daily. Under Action, select Start a program and select the batch file C:\start_vbsprogram.bat. Make sure that the task is repeated daily at the required time.
5. To program the end of the trial, do this in the Trial Control Settings. See Control the End of Tracking.
6. Leave EthoVision XT open on your screen and close all other unnecessary windows. When Windows runs the task at 8 AM, the trial starts automatically.

Notes

• If you select the option Save video in the Acquisition screen, video recording starts the moment that you click Start Trial. Depending on the condition placed immediately before the Start Track box, video recording starts some time before the actual start of tracking. In the case of Procedure 1, several hours earlier. This means that you record many hours of video when tracking is not yet active.

Programming Trial Control

Follow this section if you need more information on how to define conditions and actions in the Start-Stop trial rule.

Tip: Before defining Trial Control in EthoVision XT, draw your experimental procedure as a flowchart, where each block represents either an action or a condition which, when met, triggers other actions or conditions.

Learn About

• Conditions
• Actions
• External Commands
• Operators

See Also

• Useful Things to Know
• Re-use Trial Control Elements
• Working with Trial Control Boxes

Other Manuals

For further information, including information on controlling hardware devices such as the PhenoTyper Top Unit, the Pellet dispenser, PhenoWheel and the Lickometer, see the EthoVision XT 19 - Trial and Hardware Control - Reference Manual. To open this manual, choose Apps > Noldus > EthoVision XT 19 Other Documentation.