Frame Start Trigger Mode

The main parameter associated with the frame start trigger is the Trigger Mode parameter. The Trigger Mode parameter for the frame start trigger has two available settings: off and on.

7.4.1.1

Frame Start Trigger Mode = Off

When the Frame Start Trigger Mode parameter is set to off, the camera will generate all required frame start trigger signals internally, and you do not need to apply frame start trigger signals to the camera.

With the trigger mode set to off, the way that the camera will operate the frame start trigger depends on the setting of the camera’s Acquisition Mode parameter:

 If the Acquisition Mode parameter is set to single frame, the camera will automatically generate a single frame start trigger signal whenever it receives an Acquisition Start command.

 If the Acquisition Mode parameter is set to continuous frame, the camera will automatically begin generating frame start trigger signals when it receives an Acquisition Start command. The camera will continue to generate frame start trigger signals until it receives an Acquisition Stop command.

The rate at which the frame start trigger signals are generated may be determined by the camera’s Acquisition Frame Rate Abs parameter:

 If the parameter is not enabled, the camera will generate frame start trigger signals at the maximum rate allowed with the current camera settings.

 If the parameter is enabled and is set to a value less than the maximum allowed frame rate with the current camera settings, the camera will generate frame start trigger signals at the rate specified by the parameter setting.

 If the parameter is enabled and is set to a value greater than the maximum allowed frame rate with the current camera settings, the camera will generate frame start trigger signals at the maximum allowed frame rate.

Exposure Time Control with the Frame Start Trigger Off

When the Trigger Mode parameter for the frame start trigger is set to off, the exposure time for each frame acquisition is determined by the value of the camera’s Exposure Time Abs parameter. For more information about the camera’s Exposure Time Abs parameter, see Section 7.5 on

page 103.

Keep in mind that the camera will only react to frame start triggers when it is in a "waiting for frame start trigger" acquisition status. For more information about the acquisition status, see Section 7.1 on page 79 and Section 7.3 on page 85.

Image Acquisition Control AW00089316000

7.4.1.2

Frame Start Trigger Mode = On

When the Trigger Mode parameter for the frame start trigger is set to on, you must apply a frame start trigger signal to the camera each time you want to begin a frame acquisition. The Trigger Source parameter specifies the source signal that will act as the frame start trigger signal. The available selections for the Trigger Source parameter are:

 Software - When the source signal is set to software, you apply a frame start trigger signal to the camera by executing a Trigger Software command for the frame start trigger on the host PC.

 Line 1 - When the source signal is set to line 1, you apply a frame start trigger signal to the camera by injecting an externally generated electrical signal (commonly referred to as a hardware trigger signal) into physical input line 1 on the camera.

If the Trigger Source parameter is set to Line 1, you must also set the Trigger Activation parameter. The available settings for the Trigger Activation parameter are:

 Rising Edge - specifies that a rising edge of the electrical signal will act as the frame start trigger.

 Falling Edge - specifies that a falling edge of the electrical signal will act as the frame start trigger.

For more information about using a software trigger to control frame acquisition start, see Section 7.4.2 on page 96.

For more information about using a hardware trigger to control frame acquisition start, see Section 7.4.3 on page 98.

Exposure Time Control with the Frame Start Trigger On

When the Trigger Mode parameter for the frame start trigger is set to on and the Trigger Source parameter is set to software, the exposure time for each frame acquisition is determined by the value of the camera’s Exposure Time Abs parameter.

When the Trigger Mode parameter is set to on and the Trigger Source parameter is set to input line 1, the exposure time for each frame acquisition can be controlled with the Exposure Time Abs parameter or it can be controlled by manipulating the hardware trigger signal.

For more information about controlling exposure time when using a software trigger, see Section 7.4.2 on page 96.

By default, input line 1 is selected as the source signal for the frame start trigger. Keep in mind that the camera will only react to frame start trigger signals when it is in a "waiting for frame start trigger" acquisition status. For more information about the acquisition status, see Section 7.1 on page 79 and Section 7.3 on

Section 7.4.3 on page 98.

7.4.1.3

Setting The Frame Start Trigger Mode and Related Parameters

You can set the Trigger Mode and related parameter values for the frame start trigger from within your application software by using the Basler pylon API. If your settings make it necessary, you can also set the Trigger Source parameter.

The following code snippet illustrates using the API to set the Trigger Mode for the frame start trigger to on and the Trigger Source to input line 1:

// Select the frame start trigger

Camera.TriggerSelector.SetValue( TriggerSelector_FrameStart ); // Set the mode for the selected trigger

Camera.TriggerMode.SetValue( TriggerMode_On ); // Set the source for the selected trigger

Camera.TriggerSource.SetValue ( TriggerSource_Line1 );

The following code snippet illustrates using the API to set the Acquisition Mode to continuous, the Trigger Mode to off, and the Acquisition Frame Rate to 60:

// Set the acquisition mode to continuous frame

Camera.AcquisitionMode.SetValue( AcquisitionMode_Continuous ); // Select the frame start trigger

Camera.TriggerSelector.SetValue( TriggerSelector_FrameStart ); // Set the mode for the selected trigger

Camera.TriggerMode.SetValue( TriggerMode_Off ); // Set the exposure time

Camera.ExposureTimeAbs.SetValue( 3000 );

// Enable the acquisition frame rate parameter and set the frame rate. (Enabling // the acquisition frame rate parameter allows the camera to control the frame // rate internally.)

Camera.AcquisitionFrameRateEnable.SetValue( true ); Camera.AcquisitionFrameRateAbs.SetValue( 60.0 ); // Start frame capture

Camera.AcquisitionStart.Execute( );

You can also use the Basler pylon Viewer application to easily set the parameters.

Image Acquisition Control AW00089316000