Abstract: A communication protocol employing dummy input and output values is used in communicating blocks of data between an industrial controller and its I/O modules while preventing premature use of partially transmitted data by the I/O modules yet without the need for special handshaking type circuitry or the continuous overhead of such handshaking protocols.

Abstract: The present invention provides an efficient method of transferring multi-word data across a fixed width parallel bus normally transmitting a single word at a time by allocating part of the bus word to the transmission of a fractional address dividing the given addressing space into subaddresses or "fractional addresses". A data transfer request provides the desired fractional address and the data transfer response returns the fractional address value and the portion of the multi-word data corresponding to that fractional address.

Abstract: A controller for an injection molding machine controls the injection ram by means of profiles having segments with programmable setpoints. The injection molding machine is initially controlled during each segment in an open-loop manner. Closed-loop control is then adopted. The difference between the open-loop and the closed-loop output to the injection molding machines valves is used to change the setpoints with each cycle to improve the open-loop accuracy over time. The learning rate of change of the open-loop setpoints decreases after the initial correction. During the open loop control, the closed loop control is deactivated to prevent it from being affected by the previous open loop error.

Abstract: A controller for an injection molding machine controls the injection ram by reference to profiles having segments with programmable setpoints. The injection molding machine is initially controlled during each segment in an open-loop manner. Closed-loop control is then adopted. The difference between the process signal, e.g. ram velocity, and the setpoint at the end of each segment is used to change the current setpoint to improve the open-loop accuracy over time. The learning rate of change of the open-loop setpoints decreases after the initial correction.

Abstract: A program in a higher-level language for a programmable controller is stored as a hex-coded file in a memory in a main processor unit. The file is downloaded to a processor-based I/O logic module that translates the program into a multi-table data structure for relating the state of output devices on controlled equipment to the state of input devices on the equipment. After translation, an I/O control routine of lower-level, machine-language processor instructions is executed every 500 microseconds to control the output devices in response to changing conditions at the input devices and in response to the output functions embedded in the data structure as a result of translating the downloaded program. In a first embodiment the higher-level language is of the ladder-diagram type, while in a second embodiment the higher-level language incorporates state transition logic.