Abstract: A method and apparatus for providing an active standby control system comprising the steps of providing a first and second controller, each controller having an operating state. Each controller is operably connected to a network. Assigning a network identifier, i.e., Internet Protocol, Media Access Control address, etc., to each controller and sensing the operating state of each controller. The network identifier of each controller is determined by the operating state of each respective controller.

Abstract: A method and a device for high-speed scale conversion wherein a value N within a range of N1 and N2 is converted into a small value M within a range of M1 and M2. The method includes the step of obtaining an approximate value of M by loading the value (N−N1+2p−1) into a multi-bit shift register and right-shifting p bits. A binary search process is then used to determine the error value between the actual value of M and the approximate value of M. By avoiding actual multiplication processes, the conversion can be carried out using low-cost electronic hardware such as a microprocessor or a PROM to carry out the binary search process, a shift-register to obtain the approximate value of M, a multiplexer to receive an analog input data N and an A/D converter to convert the analog input data N into a digital data N.

Abstract: Masks used in the production of integrated circuits are analyzed and tested by a scanning spot from a laser beam comparing the position signal of the scan from a mask against a data base representing another mask which may be selected at random. Apparatus includes a laser, means to form and scan a minute spot from said laser, an x-y stage to move a mask under the scan, a detector, and means to compare scan results.