Knowledge Base

Trial Control (Without the Pulsers)

Prerequisites

• The dichroic mirror is installed.
• All components are connected and powered up.
• The LED controllers are set to TTL control.

Procedure

To control the LED directly from EthoVision XT, program the Trial Control rule using Action boxes. The duration of the light pulse is determined by a Time condition placed between the Action Output 1/2 High and Output 1/2 Low.

In the example below, LED 1 (named Device D in the Arena - Hardware Mapping window) is activated with a TTL signal Output 1 High and after 0.5 seconds it is deactivated with a TTL signal Output 1 Low. The sequence Action - Time Condition - Action has been placed within a subrule so that it can be repeated a number of times.

Notes

• Use Output 2 High/Low commands to control the LED controller connected to the DanioVision Trigger Out 2 port.
• Make sure that the Int-Ext switch near TTL on the LED controllers is set to Ext.

Trial Control (With the Pulsers)

Prerequisites

• The dichroic mirror is installed.
• All components are connected and powered up.
• The LED controllers are set to TTL - Ext control.

Procedure

1. Open all instances of the Pulser software by clicking on the desktop shortcuts Pulser A, Pulser B, and Pulser C. Each instance controls one Pulser.
2. For each instance of the software, next to Select COM Port, choose the correct COM port for the corresponding Pulser. These can be found on the Pulser or on the connection diagram.
3. Next to Select Operation Mode, choose one of the following:
   • When testing the Pulser, choose (0) Execute Pulse Sequence After START. By pressing the Start Sequence button, the LED flashes the configured sequence.
   • When running the actual trials, choose (3) Execute Pulse Sequence After Trigger HIGH, Then Stop When LOW. If you now click the Start Sequence button, the Pulser waits for a TTL trigger from EthoVision XT to start the sequence.
4. Enter the other settings in the dialog to control the pulse duration and the time between pulses. For details, see the Prizmatix Pulser/PulserPlus User Manual.
5. Start EthoVision and open the example experiment: DVOC_Optogenetics_demo_recommended.evxt.
6. In the Trial Control Settings, you find predefined routines (called subrules) to control three Pulsers. The main procedure (top row) has been configured to consecutively trigger the three Pulsers using the corresponding subrules. Make sure that:
   • The Pulsers all have the correct COM port.
   • The Pulsers are all in mode 3.
   • The Start Sequence button has been pressed.

For more information, see the chapter Optogenetics Experiments in the EthoVision XT 18 Application Manual.

Basic Subrule

A set of instructions within a subrule activates the Pulser a number of times, as specified in the Subrule Reference box. The three boxes within the subrule specify:

• An action that triggers the pulse sequence (send a High signal to a device through line Output 1 or Output 2).
• A Time condition to wait a number of seconds.
• An action that stops the pulse sequence (send a Low signal to a device through line Output 1 or Output 2).

In the following example, the subrule triggers the sequence in Pulser A through the Output 1 line, for 5 seconds.

Notes

• The name of the device selected next to Optogenetics has been renamed to 570 +520 nm in the Arena - Hardware Mapping window. This is because it controls two Pulsers: one for a LED of 570 nm through line Output 1 (from the Trigger Out 1 port in DanioVision) and one for a LED of 520 nm through line Output 2 (from the Trigger Out 2 port in DanioVision). In this example we operate the first Pulser only, using the command Output 1 High.
• You find the name 570 +520 nm in the Arena - Hardware Mapping window of the Arena Settings in the demo experiment.
• Do not forget to set the Int-Ext switch located near TTL on the LED controller to Ext.

Acquire the Data

To acquire the data, choose Acquisition > Open Acquisition.

Important Things to Check

• Make sure that the green light of the button on the LED controller is switched on.
• Make sure that the Pulser software is open on your screen. There must be one instance of Pulser software for each Pulser. If you work with two Pulsers simultaneously, two Pulser software windows must be open.
• Check that each instance of the Pulser software indicates that a COM port is selected (COM3, COM4, etc.) and shows the message "Prizmatix Pulser is connected."
• If you use the Pulser in trigger mode, in the Pulser software check that the Operating Mode is set to (3) Execute Sequence After Trigger HIGH, Then Stop When LOW. Next, click the button Start Sequence. Now the Pulser is listening to the trigger signal.

Start the Trial

To start the trial, click the Start Trial button. The optogenetics setup will be activated according to the Trial Control protocol that is active at that time.

Configure the COM Port for Each Pulser

Aim

To configure the COM port in such a way the Pulser/PulserPlus accepts commands from EthoVision XT.

Procedure

1. Connect the Pulser/PulserPlus to the PC using the USB cable with type-A to type-B connectors.
2. In the Control Panel, open the Device Manager.
3. Under Ports (COM & LPT), right-click USB Serial Port and select Properties.
4. Click the Port Settings tab.
5. Make sure that the parameters are as below, then click OK.
6. Take note of the port number (in the example above it is COM3).
7. Repeat the procedure for each Pulser/PulserPlus.

Notes

• The COM port number is retained in the Pulser, so if you disconnect the Pulsers and reconnect them, you do not have to assign the COM ports again.
• To know which COM port is assigned to which Pulser/PulserPlus device, disconnect the USB cable from one Pulser/PulserPlus. Then, re-connect it. The item that appears under Ports (COM & LPT) indicates the COM port.
• To change the COM port for a specific Pulser, in the Control Panel, open the Device Manager. Under Ports (COM & LPT), right-click the COM port, select Properties, Port Settings, then Advanced. From the COM Port Number list select the COM port among those available.

Source: DanioVision DVOC-0050 Reference Manual - Optogenetics Add-on, Noldus Information Technology