The VI manager is a system thread that must be created and invoked at the beginning of the application. To do this, call osCreateViManager() for the VI manager to allow vertical retrace interrupt to occur at an early stage. Usually, this priority should be set to OS_PRIORITY_VIMGR. The VI manager is designed to service both the VI interrupt (OS_EVENT_VI) and CPU counter interrupt(OS_EVENT_COUNTER) in the most efficient manner. Each interrupting event can be performed using osViSetEvent or osSetTimer.