Knowledge Base

The DanioVision Temperature Control Unit

Connect the Network Cable

Connect the network cable between one of the TTL ports on the back panel of the DanioVision Observation Chamber and the TTL port on the back panel of the DanioVision Temperature Control Unit.

Note: If you have the DanioVision Observation Chamber DVOC-0030 or older, connect the TTL port of the Temperature Control Unit to TTL ports 3 or 4 on the Observation Chamber. Do not use TTL port 2!

Define the Temperature Alarm in EthoVision XT

1. In EthoVision XT, create a DanioVision experiment.
2. In the Experiment Settings, under Trial Control Hardware, click the Settings button. Select the version number of your DanioVision Observation Chamber and click OK.
3. In the Device Configuration window, under Plug-in devices, choose the TTL port that you used to connect the Temperature Control Unit. Under Device Type, select DanioVision TCU (DVTCU-001x). Under Device ID, type in a name or accept the default name DanioVision TCU (DVTCU-001x) 1. Next, click OK.
4. Choose Setup > Arena Settings > Open and choose the Arena Settings you use in the experiment. In the Arena Settings window, click the Arena - Hardware Mapping button.
5. In the Arena - Hardware Mapping window, click the Add Device button.
6. In the new row that appears, under Device Type select DanioVision TCU (DVTCU-001x). Under Device Name enter a name, for example "TCU Temp Alarm". In the column A1 (or Arena 1, depending on how the first arena is named), select the Device ID that you defined above.
7. Click OK. EthoVision XT is now ready to log the alarm signals from the TCU.

Possible Alarm Signals

The following TTL signals are sent to EthoVision XT and can be used as usual in the Trial Control Settings and Analysis Profiles:

• When the current water temperature is within the normal temperature range, that is, a temperature that deviates by less than 0.5 °C from the set temperature [Tset - 0.5°C ≤ Tcurrent ≤ Tset + 0.5°C], no alarm is given. Both Low Temp Error State and High Temp Error State are false.
• When the current water temperature is more than 0.5 °C lower than the set temperature (Tcurrent < Tset - 0.5°C), a low-temperature alarm is given and Low Temp Error State becomes true.
• When the actual water temperature is more than 0.5 °C higher than the set temperature (Tcurrent > Tset + 0.5°C), a high-temperature alarm is given and High Temp Error State becomes true.
• When you turn off the Temperature Control Unit or unplug the network cable from the TTL port, both Low Temp Error State and High Temp Error State become true.

Note: During a temperature alarm, the TCU tries to bring the temperature back to the normal range, so you do not need to take any particular action.

Program the Temperature Alarm

Use a temperature alarm in the Trial Control Settings, for example to stop tracking or start an external program when a temperature alarm occurs. The following steps describe how to program the alarm based on the water temperature.

Note: During a temperature alarm, the TCU tries to bring the temperature back to the normal range, so you do not need to take any particular action with Trial Control.

1. Prerequisite: You have defined the temperature alarm in EthoVision XT.
2. Choose Setup > Trial Control Settings > Open (an existing profile) or New to create a new profile.
3. In the Trial Control Settings, under Conditions, click the button next to DanioVision TCU (DVTCU-001x).
4. The Hardware Condition window appears. In the Condition Name field, enter a name for the condition; for example, "TCU Low Temp Alarm".
5. From the DanioVision TCU list, select the device name that you defined in the Arena - Hardware Mapping window. The name listed next to DanioVision TCU could be Device A, Device B, etc., or for example "TCU Temp Alarm", depending on whether you edited the device name in the Arena - Hardware Mapping window.
6. Choose one of the following:
   • To take an action when an alarm occurs, next to Signal to Check choose either Low Temp Error State? or High Temp Error State? depending on the alarm you want to use. Then next to Signal Value select true.
   • To take an action when the number of temperature alarms reaches a certain value, next to Signal to Check choose either Low Temp Errors or High Temp Errors and select the threshold of alarm errors.
7. Insert the condition box in the Trial Control rule. Where to place the condition depends on what you want to happen. For example, if you want EthoVision to stop tracking when the condition is met, place the condition box immediately before the Action - Stop Track box.

For more information about working with conditions and actions, see Trial Control in the EthoVision XT Help and the EthoVision XT Trial and Hardware Control Reference Manual.

The Temperature Alarm in Data Analysis

You may want to visualize alarm events in the Integrated Visualization. This way you can review your trials and see if something has changed in the behavior of the larvae during or after those alarm events.

1. In an Analysis Profile, under Hardware, click the button next to Hardware State.
2. Next to Device Type, choose DanioVision TCU (DVTCU-001x).
3. Next to Device, choose the name given in the Arena - Hardware Mapping window (for example, "TCU Temp Alarm").
4. Next to Signal, choose one of the following:
   • To visualize or calculate the duration of the time that the system was in temperature error state during the trial, select Low Temp Error State for a low-temperature alarm, or High Temp Error State for a high-temperature alarm. Next to Value select true. Select false if you want to visualize or calculate the time that there was no temperature alarm.
   • To visualize or calculate the duration of the time when the system had more or less than a certain number of temperature error alarms, choose Low Temp Errors or High Temp Errors. Choose whether the number of errors was higher, lower, or equal to a threshold value. Keep the option Cumulative selected.
5. In the Trial Statistics tab, select the statistic you want and click OK.
6. Optional: Right-click the row Hardware State and select Rename. Enter a custom name; for example, "Hardware State Low Temp Alarm".
7. Choose Analysis > Results > Plot Integrated Data.

The Temperature Alarm in the Hardware Log

To export the hardware log that contains the TCU alarm events, do the following:

1. Choose Analysis > Export > Raw Data.
2. In the Raw Data Export window, make sure to select the Hardware Log check box.
3. Click Start Export to export the data.

Carry Out an Experiment

Before You Start

If you want to log temperature errors, configure EthoVision XT beforehand. See the Temperature Alarm (Optional) section for details.

Procedure

1. Set the water temperature by following the procedure described in the Normal Use with Set Water Temperature section.
2. Wait until the temperature has reached the set value and no error codes appear on the LCD screen of the TCU.
3. Insert a well plate with the larvae into the basin. To prevent air getting trapped underneath the well plate, put the back of the well plate against the wall with the shape of "∧" and place it on the basin floor, then tilt the front of the well plate down to the basin floor. As you do this, water flows into the overflow part of the basin.
4. Lower the Fresnel lens over the well plate and close the DanioVision Observation Chamber. You can now carry out a DanioVision experiment as usual.
5. If necessary, grab a background image, define the arenas, and define the Detection Settings. See also the EthoVision XT Help.
6. Choose Acquisition > Open Acquisition. Start the trial.
7. At the end of the experiment, follow the procedure in the Drain the System section. Draining prevents contamination from building up inside the system. Before you drain the system, make sure the drain tube with blue connector ends in a sink or container.

View the Temperature Alarms During the Trial

• On the Temperature Control Unit: If an error occurs in the Temperature Control Unit, an error message appears on the display. See the Feedback and Error Messages section for an explanation.
• On the EthoVision XT Screen:
  1. Choose Show/Hide > Show Dependent Variable.
  2. From the Select Hardware list, choose Hardware State. Click OK.
  3. Next to Device Type choose DanioVision TCU (DVTCU-001x). Choose the signal you want to display. Click the Statistics tab and choose the statistics of that signal that you want to display. Tip: Choose Current to display whether a temperature alarm is occurring.
  4. During acquisition, in the Analysis Results and Scoring pane click the Dependent Variables tab. There you can view the alarm state under the arena A1. Here, true means error state.

Refill the Basin During Long Experiments

The Basin Refill Tool

During prolonged DanioVision experiments, evaporation of water out of the basin could be an issue. You can compensate for evaporation by refilling the basin without opening the DanioVision Chamber.

The Basin Refill Tool (DVBR-0010) allows you to refill the basin without opening the DanioVision Chamber during an experiment. It is provided standard with the DanioVision Temperature Control Unit (DVTCU).

Important: It is possible to fill or refill the basin directly by pouring water into the basin; however, this is not practical when an experiment is running. Only use the Basin Refill Tool in combination with the DanioVision Temperature Control Unit (DVTCU).

Set Up the Basin Refill Tool

Complete these steps before starting the experiment.

1. Make sure your DanioVision basin is empty by following the instructions in the Drain the System section.
2. Disconnect the tube marked in green between the DanioVision Chamber and the Temperature Control Unit (when applicable).
3. Connect the ends of the tubes of the Basin Refill Tool to the corresponding green-marked inlets at the back of the DanioVision Observation Chamber and the Temperature Control Unit.
4. Make sure the faucet of the Temperature Control Unit is closed (Off position).
5. Fill the syringe with basin liquid, and connect it to the short faucet tube.
6. Fill the basin circuit. Tip: While the basin circuit is being filled, insert a few ml of liquid from the syringe in order to prevent air bubbles from getting into the circuit.
7. Start the experiment as usual.