Abstract: A controller system having a half-duplex serial line as a bus for transferring commands, status and data between all controllers in a planting and spraying system. A bus master connected to the serial line synchronizes each controller to the network while a base console coordinates the operation of each planting and spraying system. Separate system controllers operate in conjunction with each system accessory module to control the components of each planting and spraying system. Operation of a spray control module is controlled by the sprayer control console, operating in conjunction with a base console. A planter monitor module provides control over a plurality of components in a seed-planting system. A base console with a primary user interface and a planter controller console with a planter user interface are connected to the planter monitor module over a communications medium.

Abstract: A method and apparatus for controlling and monitoring the application rate of the anhydrous ammonia to the soil. A heat exchanger is used to maintain the anhydrous ammonia in a liquid state so that a flow control valve coupled to the heat exchanger can accurately control the rate of flow of liquid anhydrous ammonia to a manifold. Separate lines connected to the manifold distribute the liquid anhydrous ammonia to nozzles associated with earthworking tools to incorporate the ammonia into the soil. A portion of the ammonia from the manifold is directed back to an expansion chamber in the heat exchanger. The ammonia in the expansion chamber partially changes from a liquid to a vapor, thereby lowering the temperature of the ammonia in the expansion chamber and transferring heat from the liquid anhydrous ammonia in the heat exchanger to thereby maintain the ammonia in the liquid state.