Knowledge Base

The DanioVision Toplight Unit

This manual explains the setup and operation of the DanioVision Toplight (type DVTL-0020) for the DanioVision Observation Chamber DVOC-0041.

Note: The DanioVision Toplight Unit is an add-on to DanioVision; it does not come with a standard DanioVision system. For the specifications, see the DanioVision Toplight Unit specifications section.

Connect the Toplight Unit

Components

• DanioVision Observation Chamber with built-in Toplight Unit.
• Desktop power supply, TTL-to-28V interface and cabling.

Operation

With this setup, two of the LED colors, or the white light can be switched on and off from EthoVision XT. The TTL-to-28V interfaces enable switching the power from the desktop power supply.

Note: Whenever you would like to use all three colors (R-G-B) within one experiment you will need a second TTL-to-28V interface.

Important: The LEDs get hot during operation. Please let the ceiling light cool down before touching it.

Important: Do not exceed the maximum specified voltage for each color as doing so may damage the LEDs.

Setup for the White Light

1. Desktop adjustable supply set to max 18 V for white light.
2. TTL cable to free TTL port on the DanioVision Observation Chamber's (DVOC) back panel.
3. White light cable plugged in.
4. Top light cable from the DVOC's back panel.
5. Main LED power cable.

Connect the Components

The LED power cable (coming from the back of the DVOC) has 4 connectors, one for each LED color. The connectors belonging to the appropriate colors should be connected to the TTL-to-28V interface on outputs 1 and 2.

The TTL network cable (green) should be connected between the TTL-to-28V interface and port 1 on the DVOC.

A main power cable connects the desktop power supply to the input of the TTL-28V interface.

1. USB cable to EthoVision XT computer.
2. TTL cable running to TTL-to-28V interface.
3. LED power cable.

Operate the Power Supply

On the power supply the voltage can be set which determines the amount of light that the LEDs emit. The voltage may not exceed the maximum voltage for each LED color. This is 24V for the Red, Green and Blue LEDs and 18V for the white LEDs.

Important: Higher voltages may damage the LEDs. Before connecting to the mains outlet, check that the mains voltage matches the voltage setting of the power supply.

To power up, press the power button.

To Adjust the Voltage

Turn the Voltage knobs for coarse and fine adjustments. Or when in presence of one knob, press once for coarse adjustments, and press once more for fine adjustment. The actual output voltage can be read from the display.

Both Current knobs can be used to set a current limiting value (maximum current). This feature is not needed; just set to the maximum level (turn full clockwise).

If not set properly, the supply may come in Constant Current mode (CC) and limit the output voltage.

It is good practice to first set your desired voltage before actually connecting the main LED power cable to the supply. For more information, see the supply manual.

Change the Lights

To Switch Between Red, Green and Blue

To change between colors, simply unplug the current connector of the LED power cable from the TTL-to-28V interface and plug in the correct one. Each connector is labeled.

To Switch Between White and Colors

If you want to switch from RGB to white light (or vice versa), turn the complete unit in order to have the right LEDs facing down towards the well plate.

The RGB LEDs and white LEDs are mounted on the opposite sides of the same plate and can be identified by the labels white and rgb.

1. Cover the lens bracket with some protective material.
2. Untighten both left and right round black knobs to enable the unit sliding down a few centimeters, just below the camera.
3. Pull the unit out and turn it upside down (facing the preferred LEDs down).
   Important: Be careful not to twist the cable at the back. Unplug both connectors temporarily to prevent this from happening.
4. Insert the unit and slide it up again.
5. Tighten both round knobs.

Configure EthoVision XT to Control the Top Lights

1. Start EthoVision XT and create a new experiment using a template (File > New from Template). During the guided setup, choose Live Tracking, Zebrafish Larvae, DanioVision [with the type of well plate you use].

2. Choose Setup > Experiment Settings. Under Trial Control Hardware, select Use of Trial Control Hardware and choose the appropriate options. Choose the TTL port of the DVOC that you connected. You can rename Device ID to something like "Ceiling Light".

3. Choose Setup > Arena Settings. After calibrating and drawing the arenas, click Arena Hardware Mapping. Click Add Device and follow the on-screen instructions. You can rename the text under Device Name to something like "Ceiling Light". Under A1, select the device, then click OK.

4. To test the light, select Output 1 High or Output 2 High from the Command menu and click the Test button. To turn them off, select Output 1 Low or Output 2 Low.

Program the Top Lights in EthoVision XT

Choose Setup > Trial Control Settings.

Example: After 1 minute during the trial, switch the light on, then after 10 seconds switch it off.

• Under Conditions, choose Time to create a time condition (e.g. Wait 1 minute, Wait 10 seconds).
• Under Actions, choose Custom Hardware to define commands (Switch on/off). This can be done for both output 1 and output 2.
• Remember to connect all boxes with the start-stop procedure.

Create Routines

With the Subrule function you can create routines to switch the lights on and off in repeated sequences.

For more information, see the Reference Manual - Trial and Hardware Control in EthoVision XT.

Also adjust the Detection Settings (Setup > Detection Settings) before running the trials.

Source: DanioVision DVOC-0041 Reference Manual, Noldus Information Technology