21F9		4

	Cannot take vision semaphore
	1. A task having no vision semaphore tried to execute vision related commands. 2. Attempt was made to take the vision semaphore although another task already took the vision semaphore.
	1. Execute vision-related commands after taking semaphore using the TAKEVIS statement. 2. Change so that multiple programs do not attempt to take the vision semaphore at the same time.