Changing the acquisition settings at runtime

To change the acquisition settings at runtime, bind input elements directly to platform configuration settings, use a CameraSettings step, or link a Button element in the operator view to the Change Camera Settings action.

Note that you cannot directly bind operator view input elements to platform configuration settings for GenICam cameras. Instead, to adjust a GenICam camera's settings at runtime, ensure your project can call a subflowchart with a CameraSettings step.

The camera settings on the PhysicalCameraN page in the Platform Configuration dialog are typically configured during design-time, before a project is initially deployed. In most applications, these initial camera settings are not changed while a project is running. Examples of when to change a camera setting at runtime include, but are not limited to:

When entering a diagnostic or training mode, and you need to disable the hardware trigger.
When it is necessary to grab an object using different exposure times.
When some acquisition settings need to be controlled by an external device or operator input.

Changing the camera and trigger source

When using operator view input elements to trigger the grab, if you change the Camera source input, you must also change the camera's Trigger source input to match. For more information, see the template projects and the Switch between camera or disk example project; see the Switch between camera or disk example subsection of the Controlling image acquisition from the operator view section in Chapter 50: Customizing the operator view.

Stopping the grab

Some camera setting changes require the grab process to be halted; other camera settings might be modifiable while grabbing. Typically, the modifiable settings include the exposure and gain settings. Other settings, like those that modify the size or data type of the image, will typically require that grabbing is stopped. Typically, Matrox Design Assistant determines whether the grab should be stopped or not.

If you intend to halt the grab process, use the Camera step's ImageQueueAvailable output to configure your flowchart so that all pending images are processed, before executing a CameraSettings step. To guarantee that the image queue is emptied (that is, its images are discarded), you can manually halt the grab process using the StopGrab input of the CameraSettings step. Alternatively, halt the grab process by linking a Button element in the operator view to an action. For more information, see the Queuing images subsection of the Grab timing section earlier in this chapter.

Configuring the CameraSettings step

The Configuration pane of the CameraSettings step allows you to configure most of your physical camera's inputs. By default, all inputs in this pane (except the Camera name input) have the value of Unchanged. A single CameraSettings step can be configured to change one or more camera settings.

To change the Camera step's source while the project is running (such as a switch between a camera and saved images), instead of specifying an explicit source, you can specify an expression using the Advanced editor. The camera's source can also be set using platform configuration binding, a change to the Camera Name input of a CameraSettings step, or a link between a Button element in the operator view and the Set Camera Source action.

If a flowchart calls the CameraSettings step, and the operator view contains input elements that also change the camera settings, the order of operations cannot be guaranteed. In time-critical flowcharts, all camera setting changes should be performed the same way, and not through a combination of different methods. To ensure that platform settings are not modified during an inspection, use the CameraSettings step in the main or a subflowchart, instead of using the platform configuration binding feature in the operator view.