Abstract: One aspect of the present invention relates to a module for controlling two or more zones of an accumulating conveyor system. In one embodiment, the single module includes outputs to provide independent actuation signals to cause movement of two zones of the conveyor. The module includes two sensor inputs to receive article detection signals from two zones. Circuitry controls the actuation signals based upon the detection signals received. According to another aspect, a control module is provided with an input for indicating the speed of the conveyor to be used, such that programmed features of the module can be adjusted according to the speed selected. According to another aspect, a sleep mode of operation is provided wherein multiple downstream zones are awakened upon the detection of an article in an upstream zone.

Abstract: One aspect of the present invention relates to a module for controlling two or more zones of an accumulating conveyor system. In one embodiment, the single module includes outputs to provide independent actuation signals to cause movement of two zones of the conveyor. The module includes two sensor inputs to receive article detection signals from two zones. Circuitry controls the actuation signals based upon the detection signals received. According to another aspect, a control module is provided with an input for indicating the speed of the conveyor to be used, such that programmed features of the module can be adjusted according to the speed selected. According to another aspect, a sleep mode of operation is provided wherein multiple downstream zones are awakened upon the detection of an article in an upstream zone.

Abstract: An apparatus is provided for self-monitoring a communication circuit incorporating a differential driver for malfunctions with a malfunction detector located remote from the driver. The malfunction detector monitors the state of signals received at the remote location on a pair of lines coupled to the driver. Preferably, the detector includes a pair of back-to-back light emitting diodes, one of which will emit light so long as the received signals are in opposite states, and neither of which will emit light when the received signals are not in opposite states as will occur during a malfunction. The detector further preferably includes a phototransistor responsive to the diodes to provide a malfunction signal when neither diode emits light. Alternatively, the detector may comprise an exclusive-OR logic gate.