Abstract: A proximity sensor includes a transducer and a circuit having a switch that changes state in response to a presence of an object in spaced relation to the transducer. The transducer includes a magnetic form defining a generally planar surface facing a sensing zone of the sensor. The magnetic form includes a side surface that extends away from the sensing zone and an internal cavity that opens outwardly toward the sensing zone. A sensing coil is positioned within the magnetic form cavity. The transducer additionally includes a sensor housing supporting the sensing coil and the magnetic form in relation to the sensing zone. A non-ferrous metal shield is positioned inside the sensor housing to surround at least a portion of the magnetic form and enhance a sensing range of the proximity sensor. The shield has an edge that faces the sensing zone located substantially co-incident with the generally planar surface of the magnetic form.

Abstract: A sensor connection apparatus for connecting a plurality of sensors to a process controller having a bus for transferring information, wherein each sensor produces an output corresponding to a sensed condition, includes a respective sensor cable that can be connected at one end to each sensor; a concentrator having each of the sensor cables connected thereto; the concentrator being connected to the bus; the concentrator comprising a circuit for producing for each sensor and associated sensor cable connected thereto a first signal in response to the sensor output and a second signal that corresponds to a sensor cable condition; the circuit further operating to couple the first and second signals for each sensor connected to the concentrator onto the bus for access by the process controller. In one embodiment, the concentrator transmits data to the process controller using a standardized communications protocol, such as CAN, using a microcontroller and transceiver.