I was modifying Steven Hassenplug's Line Following block (http://www.teamhassenplug.org/NXT/) and noticed that it only acquires and releases the port semaphore for one of the motors. I assume it should do both motors.
I can use the Pow2 vi and OR the outputs to acquire the semaphore for both motors. However, the only way I can figure out to release both of them is to replace the Motor Release vi with the Move Release vi (adding the Bits To List vi to convert the Motor Bits created by OR ing the motors). Attached is my modified sub vi.
Since I'm not sure how to verify that the semaphores are being released, hopefully someone can tell me if this will work or tell me how to release the semaphores of two motors.