Acquisition Start, Stop, and Abort#

The Acquisition Start, Stop, and Abort commands allow you to control image acquisition.

Using the Feature#

Starting Image Acquisition#

To switch on image acquisition, execute the AcquisitionStart command.

After the command has been executed, the camera waits for trigger signals. Trigger signals can either be generated internally by the camera (free run) or applied externally (triggered image acquisition).

Stopping Image Acquisition#

To switch off image acquisition, execute the AcquisitionStop command. When the command is executed, the following occurs:

On area scan cameras:

• If the camera is not currently acquiring a frame, image acquisition is switched off immediately.
• If the camera is currently reading out image data, the readout process will be allowed to finish. Afterwards, image acquisition is switched off.
• If the camera is currently exposing a frame:
  • On some camera models, executing an AcquisitionStop command aborts exposure. In this case, the camera stops exposing immediately and starts reading out image data. The readout process will be allowed to finish. Afterwards, image acquisition is switched off.
  • On some camera models, you can configure whether executing an AcquisitionStop command aborts exposure or not. To do so, set the AcquisitionStopMode parameter to AbortExposure or Complete.

On line scan cameras:

• The AcquisitionStopMode parameter for line scan cameras is always set to Immediate.
• If the camera is not currently acquiring a frame, image acquisition is switched off immediately.
• If the camera is currently exposing a line, the AcquisitionStop command leads to the following for all racer 2 line scan cameras:
  The exposure of the current line is completed. Acquisition stops immediately. The last acquired line is transmitted to the host computer.
• In addtion, for racer 2 S cameras with GigE interface, the following is true:
  Only the lines acquired up to the point when the command was executed are delivered to the host computer. This may result in a partial frame being transmitted.

Aborting Image Acquisition#

To abort image acquisition, execute the AcquisitionAbort command (if available).

On area scan cameras, the following occurs when the command is executed:

• If the camera is not currently acquiring a frame, image acquisition is switched off immediately.
• If the camera is currently exposing a frame, the camera stops exposing immediately. The readout process, if already started, is aborted. The current frame will be incomplete and is not transmitted to the host computer. Afterwards, image acquisition is switched off.
• If the camera is currently reading out image data, the camera stops the readout process immediately. The current frame will be incomplete and is not transmitted to the host computer. Afterwards, image acquisition is switched off.

On line scan cameras, the following occurs when the command is executed:

• If the camera is not currently acquiring a line, image acquisition is switched off immediately.
• If the camera is currently exposing a line, the camera stops exposing immediately. The readout process, if already started, is continued. Only the lines acquired up to the point when the command was executed are delivered to the host computer. For line scan cameras with GigE interface, this may result in a partial frame being transmitted. Afterwards, image acquisition is switched off.
• If the camera is currently reading out image data, the camera continues the readout process until all lines acquired up to the point when the command was executed are delivered to the host computer. For line scan cameras with GigE interface, this means that the current frame may be incomplete (partial frame).
  Afterwards, image acquisition is switched off.

Specifics#

Show all camera models

Sample Code#

// Configure continuous image acquisition on the cameras
camera.AcquisitionMode.SetValue(AcquisitionMode_Continuous);
// Switch on image acquisition
camera.AcquisitionStart.Execute();
// The camera waits for trigger signals
// (...)
// Switch off image acquisition
camera.AcquisitionStop.Execute();
// Switch image acquisition back on
camera.AcquisitionStart.Execute();
// The camera waits for trigger signals
// (...)
// Abort image acquisition
camera.AcquisitionAbort.Execute();

INodeMap& nodemap = camera.GetNodeMap();
// Configure continuous image acquisition on the cameras
CEnumParameter(nodemap, "AcquisitionMode").SetValue("Continuous");
// Switch on image acquisition
CCommandParameter(nodemap, "AcquisitionStart").Execute();
// The camera waits for trigger signals
// (...)
// Switch off image acquisition
CCommandParameter(nodemap, "AcquisitionStop").Execute();
// Switch image acquisition back on
CCommandParameter(nodemap, "AcquisitionStart").Execute();
// The camera waits for trigger signals
// (...)
// Abort image acquisition
CCommandParameter(nodemap, "AcquisitionAbort").Execute();

// Configure continuous image acquisition on the cameras
camera.Parameters[PLCamera.AcquisitionMode].SetValue(PLCamera.AcquisitionMode.Continuous);
// Switch on image acquisition
camera.Parameters[PLCamera.AcquisitionStart].Execute();
// The camera waits for trigger signals
// (...)
// Switch off image acquisition
camera.Parameters[PLCamera.AcquisitionStop].Execute();
// Switch image acquisition back on
camera.Parameters[PLCamera.AcquisitionStart].Execute();
// The camera waits for trigger signals
// (...)
// Abort image acquisition
camera.Parameters[PLCamera.AcquisitionAbort].Execute();

/* 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 */
/* Configure continuous image acquisition on the cameras */
errRes = PylonDeviceFeatureFromString(hdev, "AcquisitionMode", "Continuous");
CHECK(errRes);
/* Switch on image acquisition */
errRes = PylonDeviceExecuteCommandFeature(hdev, "AcquisitionStart");
CHECK(errRes);
/* The camera waits for trigger signals */
/* (...) */
/* Switch off image acquisition */
errRes = PylonDeviceExecuteCommandFeature(hdev, "AcquisitionStop");
CHECK(errRes);
/* Switch image acquisition back on */
errRes = PylonDeviceExecuteCommandFeature(hdev, "AcquisitionStart");
CHECK(errRes);
/* The camera waits for trigger signals */
/* (...) */
/* Abort image acquisition */
errRes = PylonDeviceExecuteCommandFeature(hdev, "AcquisitionAbort");
CHECK(errRes);

# Configure continuous image acquisition on the cameras
camera.AcquisitionMode.Value = "Continuous"
# Switch on image acquisition
camera.AcquisitionStart.Execute()
# The camera waits for trigger signals
# (...)
# Switch off image acquisition
camera.AcquisitionStop.Execute()
# Switch image acquisition back on
camera.AcquisitionStart.Execute()
# The camera waits for trigger signals
# (...)
# Abort image acquisition
camera.AcquisitionAbort.Execute()

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