Event Notification#

The Event Notification camera feature allows you to enable camera events and event messages.

Using the Feature#

Enabling Event Notification#

1. Set the EventSelector parameter to one of the following values (if available):
   • ActionLate
   • CriticalTemperature
   • EventOverrun or Overrun
   • ExposureEnd
   • FrameBufferOverrun
   • FrameBurstStart
   • FrameBurstStartOvertrigger
   • FrameBurstStartWait
   • FrameStart
   • FrameStartOvertrigger
   • FrameStartWait
   • FrameTriggerMissed
   • OverTemperature
   • TemperatureStatusChanged
   • Test
2. Set the EventNotification parameter to On.
3. Repeat steps 1 and 2 for all types of event notifications that you want to enable.
4. Implement event handling in your application:
   • For a C++ sample implementation, see the Grab_CameraEvents (C++) code sample in the pylon API Documentation.
   • For a C and C .NET sample implementation, see the Events Sample (C) and Grab Using Events for USB or GigE Camera (.NET) code samples in the pylon API Documentation.

Available Events#

Action Late Event#

If available, the Action Late event occurs if the camera receives a scheduled action command with a timestamp in the past.

When this event occurs, the corresponding message contains a timestamp indicating the time when the event was generated.

Critical Temperature Event#

If available, the Critical Temperature event occurs if the camera's temperature state has reached a critical level.

When this event occurs, the corresponding message contains a timestamp indicating the time when the event was generated.

Event Overrun Event#

If available, the Event Overrun event (also called Overrun event) occurs if the camera's internal event queue has overrun. This happens if events are generated at a very high frequency and there isn't enough bandwidth available to send the events.

The event overrun event is a warning that events are being dropped. The notification contains no specific information about how many or which events have been dropped.

When this event occurs, the corresponding message contains a timestamp indicating the time when the event was generated.

Exposure End Event#

The Exposure End event occurs whenever an image has been exposed.

When this event occurs, the corresponding message contains a timestamp indicating the time when the event was generated. Also, it contains a frame ID indicating the number of the image that has been exposed.

Frame Buffer Overrun Event#

If available, the Frame Buffer Overrun event occurs whenever frames were skipped because the camera's internal frame buffer was already full.

If the host controller doesn't retrieve the acquired images in time, the camera buffers images in its internal frame buffer. When the internal frame buffer is full, the camera will start skipping newly acquired sensor data.

When this event occurs, the corresponding message contains a timestamp indicating the time when the event was generated.

Frame Burst Start (= Acquisition Start) Event#

If available, the Frame Burst Start event occurs whenever a Frame Burst Start trigger has been generated by the camera (free run) or applied externally (triggered image acquisition).

When this event occurs, the corresponding message contains a timestamp indicating the time when the event was generated.

Frame Burst Start Overtrigger (= Acquisition Start Overtrigger) Event#

If available, the Frame Burst Start Overtrigger event occurs whenever the Frame Burst Start trigger has been overtriggered. This happens if you apply a Frame Burst Start trigger signal when the camera is not ready to receive the signal.

When this event occurs, the corresponding message contains a timestamp indicating the time when the event was generated.

Frame Burst Start Wait (= Acquisition Start Wait) Event#

If available, the Frame Burst Start Wait event occurs whenever the camera is ready to receive a Frame Burst Start trigger signal.

When this event occurs, the corresponding message contains a timestamp indicating the time when the event was generated.

Frame Start Event#

The Frame Start event occurs whenever a Frame Start trigger has been generated by the camera (free run) or applied externally (triggered image acquisition).

When this event occurs, the corresponding message contains a timestamp indicating the time when the event was generated. On Basler ace 2 cameras, it also contains a frame ID indicating the number of the image that has been exposed.

Frame Start Overtrigger Event#

If available, the Frame Start Overtrigger event occurs whenever the Frame Start trigger has been overtriggered. This happens if you apply a Frame Start trigger signal when the camera is not ready to receive the signal.

When this event occurs, the corresponding message contains a timestamp indicating the time when the event was generated.

Frame Start Wait Event#

If available, the Frame Start Wait event occurs whenever the camera is ready to receive a Frame Start trigger signal.

When this event occurs, the corresponding message contains a timestamp indicating the time when the event was generated.

Frame Trigger Missed Event#

This event is identical to the Frame Start Overtrigger event, only the name differs.

Over Temperature Event#

If available, the Over Temperature event occurs if the camera's temperature state has reached the over temperature level.

When this event occurs, the corresponding message contains a timestamp indicating the time when the event was generated.

Temperature Status Changed Event#

If available, the Temperature Status Changed event occurs whenever the camera's temperature state has changed.

When this event occurs, the corresponding message contains the EventTemperatureStatusChangedStatus parameter. This parameter indicates the new temperature status that applies after the event was raised:

• Ok: The temperature status changed to Ok.
• Critical: The temperature status changed to Critical.
• Error: The temperature status changed to Error.

Also, the corresponding message contains a timestamp indicating the time when the event was generated.

Test Event#

If available, the Test event allows you to test the Event Notification feature.

When this event occurs, the corresponding message contains a timestamp indicating the time when the event was generated.

To test event notification:

1. Execute the TestEventGenerate command.
2. Handle the Test event in your application.

Specifics#

Show all camera models

Sample Code#

// Enable the Exposure End event notification
camera.EventSelector.SetValue(EventSelector_ExposureEnd);
camera.EventNotification.SetValue(EventNotification_On);
// Enable the Critical Temperature event notification
camera.EventSelector.SetValue(EventSelector_CriticalTemperature);
camera.EventNotification.SetValue(EventNotification_On);
// Now, you must implement event handling in your application.
// For C++, C, and .NET sample implementations, see the "Grab_CameraEvents" and
// "Events" code samples in the pylon API Documentation

INodeMap& nodemap = camera.GetNodeMap();
// Enable the Exposure End event notification
CEnumParameter(nodemap, "EventSelector").SetValue("ExposureEnd");
CEnumParameter(nodemap, "EventNotification").SetValue("On");
// Enable the Critical Temperature event notification
CEnumParameter(nodemap, "EventSelector").SetValue("CriticalTemperature");
CEnumParameter(nodemap, "EventNotification").SetValue("On");
// Now, you must implement event handling in your application.
// For C++, C, and .NET sample implementations, see the "Grab_CameraEvents" and
// "Events" code samples in the pylon API Documentation

// Enable the Exposure End event notification
camera.Parameters[PLCamera.EventSelector].SetValue(PLCamera.EventSelector.ExposureEnd);
camera.Parameters[PLCamera.EventNotification].SetValue(PLCamera.EventNotification.On);
// Enable the Critical Temperature event notification
camera.Parameters[PLCamera.EventSelector].SetValue(PLCamera.EventSelector.CriticalTemperature);
camera.Parameters[PLCamera.EventNotification].SetValue(PLCamera.EventNotification.On);
// Now, you must implement event handling in your application.
// For C++, C, and .NET sample implementations, see the "Grab_CameraEvents" and
// "Events" code samples in the pylon API Documentation

/* Macro to check for errors */
#define CHECK(errc) if (GENAPI_E_OK != errc) printErrorAndExit(errc)
GENAPIC_RESULT errRes = GENAPI_E_OK;  /* Return value of pylon methods */
/* Enable the Exposure End event notification */
errRes = PylonDeviceFeatureFromString(hdev, "EventSelector", "ExposureEnd");
CHECK(errRes);
errRes = PylonDeviceFeatureFromString(hdev, "EventNotification", "On");
CHECK(errRes);
/* Enable the Critical Temperature event notification */
errRes = PylonDeviceFeatureFromString(hdev, "EventSelector", "CriticalTemperature");
CHECK(errRes);
errRes = PylonDeviceFeatureFromString(hdev, "EventNotification", "On");
CHECK(errRes);
/* Now, you must implement event handling in your application. */
/* For C++, C, and .NET sample implementations, see the "Grab_CameraEvents" and */
/* "Events" code samples in the pylon API Documentation */

# Enable the Exposure End event notification
camera.EventSelector.Value = "ExposureEnd"
camera.EventNotification.Value = "On"
# Enable the Critical Temperature event notification
camera.EventSelector.Value = "CriticalTemperature"
camera.EventNotification.Value = "On"
# Now, you must implement event handling in your application.
# For C++, C, and .NET sample implementations, see the "Grab_CameraEvents" and
# "Events" code samples in the pylon API Documentation

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