Abstract: A system and method for automatically processing and tracking the processing of requests are described. Instructions for processing requests of interest are received. In a preferred embodiment, the requests are product change notices (PCNs). A request from a source of requests is received. Relevant information is extracted from the received request. An entry in a database is created, and the extracted information is stored in the database entry. The stored information is validated to determine if the received request is valid, and the received request is rejected if the stored information is not valid. If the stored information is valid, then additional information related to the request is retrieved from a source of additional information, and this retrieved information is stored in the database entry. Messages are sent to other users involved with processing the received request. Each message includes the database entry and optionally a request for a response.

Abstract: A detector circuit detects one of two impedances presented by a communication line for each one of a plurality of operative modes. The circuit comprises a network having three parallel branches. The first includes two serially connected resistors which develop a reference potential in response to current flowing in the line. The second branch includes two oppositely poled light-emitting diodes (LEDs) which form a sensor to detect current flow in the line in either direction. The third branch includes a varistor to limit the magnitude of unexpected potentials applied to the sensor. When the magnitude of the reference potential is sufficient to forward bias either LED and the magnitude of the current is greater than a predetermined level, one of the LEDs will generate an output signal representative of one impedance of the line. Otherwise, the LEDs generate a second output representative of the other impedance of the line in a particular operative mode.