A programmable sequence control apparatus including a first memory device for storing sequence program instructions, an input/output device, a relay ladder operation device for executing logic operations for a relay ladder circuit having n rows and m columns (wherein n and m are positive integers) in accordance with the program instructions, and a control device for delivering control signals to the relay ladder operation device, is so constructed that the control device includes a memory device for storing contact data and branch data for one column j (wherein j=1, 2, . . . , m) of the relay ladder circuit temporarily, the relay ladder operation device includes first and second registers of a series-in and parallel-out mode which receive and store the contact data and the branch data for the column j, respectively, a third register normally operable in a parallel-in and parallel-out mode, and a gate circuit including logic elements for executing logic operations for the column j based on the parallel delivered outputs of the first and second registers and a third register storing the operation results for the preceding column (j-1), and the relay ladder operation device repeats the aforementioned operation for all of the columns of the relay ladder circuit.
A control system for a programmable control device (10) executing a user program cyclically, wherein a data bit is provided in a memory space which can be accessed by a user program, the data bit is made "ON" in an operation mode and made "OFF" in a stop mode. The data bit is programmed with an AND condition for an output signal (Q1) to be made "OFF" in the stop mode, and the operation mode is shifted to the stop mode only after having made the data bit "OFF" and having executed the user program for one or more scans.
In the sequence program (ladder circuit), in order to give a common address between contacts of the ladder circuit longitudinally and store states before and after the processing of the contact in the ladder circuit, two types of memories corresponding to addresses at the both ends of the contact are provided and a compiler for classifying the processing into the five types and a sequence execution unit for processing a machine language of the compiler are further provided so that execution can be made even if an output instruction is provided in an intermediate portion of the ladder circuit.
An information handling system for a memory includes an input section, a storage section and an output section. The information handling system is constructed to selectively provide a direct signal link between the input section and the output section without storage of the transmitted signal. Control circuits are provided to selectively cause storage of data, read-out of data, data pass-through without storage or the simultaneous carrying out of a plurality of the aforementioned operations.
The method and device are used to control outputs to a plurality of output devices relative to inputs and for synchronizing the updating of selected outputs with the occurrence of an external event. An interrupt signal is derived from an external event at one or more input devices and supplied to a micro-computer. A user ladder program is provided in the device for controlling the outputs and one or more interrupt zones are provided in the ladder program and are immediately responsive to the interrupt signal for instantaneously updating selected outputs. Each interrupt zone includes enabling means, an opening boundary, addresses of inputs to be fetched, a body of instructions and a closing boundary.
A programmable controller having a memory for storing a sequence program in which messages are programmed with a processor for performing sequence control by successively executing the sequence program stored in the memory, and a display unit for displaying a ladder diagram corresponding to the sequence program of the memory as well as messages. The processor executes the sequence program and, when an alarm is sensed, causes the display unit to display a portion of a ladder associated with the alarm in accordance with alarm message data contained in the sequence program, thereby executing a rapid retrieval operation without relying upon the operator.
