Why can it sometimes take so long for scout, pilot, or runner cameras to react to an acquisition stop command?

You may find that the execution of an acquisition stop command while running a camera in continuous mode takes longer than you would expect on cameras such as the scout, pilot, or runner (depending on the camera model - up to 58.5 ms, for example, on the piA2400-17xx).

This behavior is not a bug, but rather is standard camera operation. When an acquisition stop command is executed on a camera running in continuous mode, the camera’s reaction to the command depends very much on the condition the camera is in at the moment the command is received. For example, if the camera is in the process of exposing the sensor to light when the command is executed - it will just stop the exposure. So in this case, the execution of the acquisition stop command will take just a very short time.

However, if the acquisition stop command is received while sensor readout or image transmission is taking place, it will take quite a bit longer for the camera to stop, i.e., Frame Readout Time (whatever remains of it) + Frame Transmission Time. So in the worst case, it can take almost the full frame readout time for a given camera model before the camera reports completion of the acquisition stop command.