An SCADA web HMI system includes a web browser for displaying an HMI screen. An integrated part identifier generation unit generates a new integrated part identifier when attribute identifiers of first part data and second part data are identical. A part data change unit changes part identifiers of the first part data and the second part data to the integrated part identifier. An integrated item name generation unit generates an integrated item name in which a screen identifier of the HMI screen, the integrated part identifier, and the identical attribute identifier are combined. The web browser changes, when a PLC signal received from a programmable logic controller corresponds to the integrated item name, a display state of the first part based on first display information and changes a display state of the second part based on second display information, according to the value of the received PLC signal.

A programmable logic controller includes an error detection unit, a data memory storing error occurrence information indicating, for each error kind, whether the error detection unit has detected an error, an error automatic cancellation processing unit determining whether an error factor of each error has been eliminated and, when the error factor has been eliminated, performing an error cancellation process including a process to change the error occurrence information to error non-occurrence, and an error-automatic-cancellation-permission determination unit referring to an error automatic cancellation permission setting and determining, when the error detection unit detects an error, whether the error is canceled by the error automatic cancellation processing unit on the basis of the error automatic cancellation permission setting, wherein the error automatic cancellation processing unit performs the error cancellation process on the error that the error-automatic-cancellation-permission determination unit has determined that the error automatic cancellation processing unit is to cancel.

A method for influencing a control program having a plurality of first functions and at least one of the first functions is configured to control an actuator, and a memory is provided and the memory has memory regions occupied by subprograms assigned to the first functions, whereby there is a branch address in the program code of the control program when one of the first functions is called up that points to a memory address of the subprogram associated with the function call. The control program is analyzed for the occurrence of function calls, and the branch addresses, associated with the function calls, and addresses of the return commands are ascertained. One of the first functions is selected to be deleted. The first function is replaced by a second function, in which the program code of the selected first function is overwritten by the program code of the second function.

A dual redundant computer safety relay box system includes first and second fail-safe computing systems (FSCs) individually mounted to first and second printed circuit boards. Each FSC includes two computing modules (CPUs) designated as a first CPU and a second CPU. The first and second FSC's are both connected to a safety relay box. The printed circuit boards are isolable from each other permitting maintenance on one of the printed circuit boards while operation of the FSC of the other printed circuit board is maintained. In each FSC a health signal generated from the first and second printed circuit boards of the first and second CPUs defines a multi-level dynamic pulse signal. Presence of the dynamic pulse signal produces an output identified as each of a first and a second healthy indication signal from each of the CPUs of one of the first or second FSCs.

A system construction assistance apparatus includes a first display screen, a second display screen, and a processing section displaying units each belonging to one of categories on the first display screen such that the units are sorted by category, receiving a first input to select one unit from the units displayed on the first display screen, generating a system configuration diagram on the basis of the received first input, and displaying the generated system configuration diagram on the second display screen. After a first input is newly received and before a next first input is received, the processing section predicts a category to which a unit to be selected by the next first input belongs on the basis of first inputs received in a past and presents the predicted category as a candidate category to a user.

A system construction assistance apparatus includes a first display screen, a second display screen, and a processing section displaying units each belonging to one of categories on the first display screen such that the units are sorted by category, receiving a first input to select one unit from the units displayed on the first display screen, generating a system configuration diagram on the basis of the received first input, and displaying the generated system configuration diagram on the second display screen. After a first input is newly received and before a next first input is received, the processing section predicts a category to which a unit to be selected by the next first input belongs on the basis of first inputs received in a past and presents the predicted category as a candidate category to a user.

A controller with enhanced reliability of access to a database system. A programmable logic controller (PLC) accessible to a database accesses a database (DB) server in response to an event in which a user program calls a DB access processing program. The DB access processing program stores status information indicating a status of accesses to the DB server in a nonvolatile memory, in accordance with an instruction of the user program. When a power interruption occurs, the PLC can obtain a status of accesses to the DB server at the timing of the occurrence of the power interruption by referring to the status information. Then, the PLC, for example, re-sends a structured query language (SQL) sentence, depending on the access status.

The PLC communication system associated with the invention is characterized in that the system comprises a programmable logic controller (PLC), a plurality of processing devices, at least three communication processing nodes provided at the PLC and at the plurality of processing devices respectively to establish communication of the PLC and each of the processing devices and an interconnecting device and a plurality of communication lines for connecting the communication processing nodes with one another to establish data communication among the communication processing nodes. The PLC detects a state of communication failure and a display device displays an abnormal portion in a communication route based on the number of occurrences of the state of communication failure in respective interconnecting device and plurality of communication lines.

Different devices or subsystems, including programmable industrial controllers, are connected to a common network. Each connected device has the capability for autonomous or quasi-autonomous action based on a common pool of information accessible on the network. For example, all or a subset of devices connected to the network may periodically broadcast status data over the shared network medium; status data may include the current state of the controller and/or environmental conditions that the controller monitors.

An electronic device having a temperature management function includes a platform controller hub (PCH), a complex programmable logic device (CPLD) and a hardware monitor. The PCH includes a first temperature sensor for sensing the first temperature of the PCH. The CPLD includes a memory and is coupled to the PCH. The CPLD reads the first temperature sensed by the first temperature sensor and saves it in the memory. The CPLD searches for an offset value in the memory and generates a device temperature according to the offset value and the first temperature. The hardware monitor is coupled to the CPLD and reads the device temperature.