Abstract: A plurality of monitoring devices are connected to respective pieces of switchyard equipment and associated with a common communications network. A remote host computer is connected to the network to bidirectionally communicate with each monitoring device. The communications network is the existing power line used for delivering power and control signals to the switchyard equipment. Each monitoring device includes testing and/or monitoring circuitry for testing and/or monitoring one or more conditions of the piece of switchyard equipment and generating condition data therefrom, a storage device for storing the generated data, and a transmitter adapted to transmit the data to the remote location via the power line. The remote host computer receives the data transmitted to the remote location and stores the received data therein in a database format. The monitoring device can request previously sent data from the remote host computer.

Abstract: A method for detecting the presence of and removing jams in a chute used for transporting a flowable material includes a jam breaking device which travels within the chute. An acoustic detector detects acoustic signals associated with movement of the material through the chute and compares the acoustic signal to a stored acoustic signature representative of an unjammed chute. If a jam is detected, the jam breaking device is operated for a fixed period of time to attempt to break up the jam. After another fixed period of time, a new acoustic signal is detected and processed to determine whether the jam is still present. If so, the jam breaking device is moved a predetermined distance along the chute and operated again. These steps are repeated as long as each new acoustic signal indicates that the jam is still present.