A valve provides multiple channels that allow alternating, or in some cases, simultaneous, fluid flow functions to a port of an instrument, without the requirement of manual manipulation of the valve by the user. A floating member such as a ball having magnetic affinity for a portion of the valve is positioned in a home, or normal, position by a magnetic field, where it remains until acted on by fluid pressure. The ball in the home position opens other channels of the device. Under fluid pressure in the channel in which the balls home position is located, the ball is displaced, obstructing at least one of the other channels, while opening the channel to permit a fluid flow through the channel. When the fluid pressure in the channel is terminated, the ball returns to the home position, and other ports are opened.
