Patent ID: 8032261
Filing Date: 2011-10-04
Classification: G05D,G06F

Abstract:
1. A cooling system for a storage cabinet, such cooling system comprising: a fan unit, such fan unit having a pair of terminals, a first one of the pair of terminal for receiving a signal having a first protocol representative of a commanded fan speed and a second one of the pair of terminals transmitting a signal having a second protocol representative of actual fan speed; a sensor disposed to sense temperature with the cabinet; a system controller, responsive to the sensed temperature and the actual fan speed, for producing control signals for fan to adjust fan speed in accordance with the sensed temperature and the actual fan speed, the system controller producing the control signals in one of a plurality of different predetermined two-wire communication protocols; a fan controller; two-line communication bus coupling the control signals between the system controller and the fan controller; wherein the fan controller has a first pair of terminals connected to the two-line communication bus and a second pair of terminals connected to pair of terminals of the fan unit; and wherein the fan controller detects the one of the plurality of predetermined two-wire communication protocols on the two-wire communication bus and provides, in accordance with such detection, the first terminal of the pair of fan unit terminals with the signal having the first protocol representative of the commanded fan speed and transmits the signal at the second terminal of the pair of fan unit terminals having the second protocol representative of the actual fan speed to the system controller via the communication bus.