Abstract: A method of communicating between a plurality of devices in a controller area network is disclosed. The method includes authorizing a first device to transmit messages with a first identifier over the network, the first device transmitting a first message with the first identifier and a first value, and the devices which receive the first message assuming the first value as their respective values. The method may be used with a number of devices and a listening device in a system. At startup of the system, any device which saved its value in a non-volatile memory will become the master of the identifier and transmit a message with the value over the network. Devices which did not save their values in non-volatile memories will transmit requests for the data value. If they do not receive any response, they will become the master and transmit messages with their data. Devices which receive the message will assume the value as theirs.

Abstract: A detector for detecting, in images of camera scanned scenes, edges which extend generally parallel to the scanning lines. Accordingly, by comparing an undelayed signal to a first signal delayed by slightly more than one scan line, a differential can be obtained at a 45 degree angle going downward from the left to the right of the image. By delaying a second signal slightly less than one scan line, the differential becomes 45 degrees going downward from the right to the left of the image. These differentials are utilized to detect edges extending parallel to the scan lines.

Abstract: A self contained apparatus is utilized for direct movement on and across a roof surface to lay on the roof surface a continuous sheet or roofing material being removed from a roll guided at each of its ends by this apparatus, and being heated, before being removed, by a heating assembly pivotally supported by the apparatus and pivotally adjusted, so the distance between the roll and the heating assembly is maintained. An inclined A frame of the apparatus has a handle at its apex, and bottom opening slots at its lower ends to fit over the ends of a shaft on which the roll of roofing material is positioned. There is a depending wheel assembly below the handle serving to complete the triangular support of this self contained apparatus. The inclined A frame is pivoted about the wheel assembly to clear the bottom opening slots from the shaft ends and vice versa, when a roll of roofing material is being supplied, withdrawn, and/or adjusted to a different set of slots.