Why am I unable to configure my DCAM's ShutterAbsolute property with a valid value using the Image Acquisition Toolbox?

I am unable to properly configure the ShutterAbsolute property of my DCAM device using the Image Acquisition Toolbox. In particular, the constraint values for the property vary when I alter the FrameRate of the device.

For example, if the device is configured to acquire 30 fps, the shutter's absolute value boundary may be from .000125 seconds to .033 seconds. Conversely, if the device is configured to acquire 15 fps, the shutter's absolute value boundary may be from .034 seconds to .066 seconds.

However, after creating the object, when I modify the FrameRate, the constraint values do not change.

Answer 1

[MathWorks Support Team]

Because the ShutterAbsolute property's minimum and maximum contraint values are determined at the time when the videoinput object is created, the minimum and maximum contraint value will depend on the frame rate configuration stored by that camera's internal register at that time. That frame rate configuration should be the last configuration used by the device.

If you know that your shutter's absolute value is valid but that value falls outside the minimum or maximum ShutterAbsolute constraint, then do the following:

1. Configure the FrameRate property to the rate such that the absolute value you want is no slower than that frame rate and choose the lowest frame rate that meets that condition. For example, if you want a shutter absolute value of 0.100 seconds, and the available frame rates are 3.75 fps, 7.5 fps, 15 fps, and 30 fps, you should choose the 7.5 fps.

2. If the device is not already previewing, call PREVIEW. The device needs to start acquiring data in order to configure the new frame rate.

3. Call IMAQRESET.

4. Create the video input object for the device.

5. Configure the FrameRate property back to the value that contains the absolute value you want.

6. Configure the ShutterAbsolute property with the absolute value you want.