Disclosed systems and methods for monitoring an execution system of a programming logic controller (PLC), the method comprising: accessing, by a security module, the PLC execution system and dividing the code and data of the PLC execution system into a plurality of program modules; modifying, by the security module, data exchange interfaces of the program modules used for the interaction between the program modules and the resources of the operating system such that said interaction occurs through the security module, while a format of the data being exchanged complies with a format specified by the security module; and monitoring, by the security module, the execution of the PLC execution system, including monitoring the interaction of the program modules of the PLC execution system with each other and with the resources of the operating system.

The present invention relates to a method for automatic translation of ladder logic to a SMT-based model checker in a network comprising defining (10) the topology of the network as an enriched network topology based on packets exchanged in the network, extracting (20) a program from the packets relating to a PLC in the network and identifying inputs, outputs, variables and a ladder diagram of the PLC, translating (30) the inputs, outputs, variables and ladder diagram into a predefined formal model, wherein the predefined formal model is a circuit-like SMT-based model checker, and wherein the translating (30) comprises translating the set of data types of the program according to a predefined model set of data types of the circuit-like SMT-based model checker, translating the inputs of the PLC as model inputs of the circuit-like SMT-based model checker of the same type, translating the outputs of the PLC as model output latches of the circuit-like SMT-based model checker of the same type, translating the variables of the PLC as model variable latches of the circuit-like SMT-based model checker of the same type, translating comparators and arithmetic operators of the ladder diagram into a plurality of predefined model functions of the circuit-like SMT-based model checker, translating contacts and coils of the ladder diagram according to predefined model recursive procedures relating to the predefined model set of data types, the model inputs, the model output latches, the model variable latches and the plurality of predefined model functions, wherein the contacts are switches that can block or allow the flow of the current in a connection and each of the contacts is controlled by a Boolean input or variable, and wherein the coils are assignments to Boolean variables.

Provided is a simulation technique that allows the program verification to be more efficiently performed. A simulation system includes: a simulator that executes simulation of an operation of one or more devices; a data input unit that obtains one or more execution times in the simulation, positional information of each one of objects in the simulation, and a value of each one of one or more variables referred to by a program to operate the devices; a data recorder that stores, as a first log, positional information of the objects and value of the variables for each of the one or more execution times in a manner that positional information and value are associated with each other; and a displayer that displays positional information of the objects and value of the variables for each of the one or more execution times included in first log.

A method in an industrial process control system comprises creating a control strategy for an industrial process, running a simulation of the control strategy, and rewinding the simulation of the control strategy. Rewinding the control strategy includes setting the simulation to a previous point in time of the simulation. The method further includes displaying the simulation on a display. The method can further comprise capturing process variable states from an online process and fast forwarding the simulation of the control strategy, wherein fast forwarding the control strategy includes progressing the simulation forward from a state represented by the captured process variable states.

A controller of a PC displays program elements of a ladder program and an electrical connection state thereof on a display, detects an instruction designating a first program element, determines whether the first program element is in an electrically connected state or an electrically disconnected state, specifies one or more causal elements according to whether the first program element is in an electrically connected state or an electrically disconnected state, and displays the specified one or more causal elements on the display in a state discernible from other program elements.

The present invention relates to a computer program for producing a graphical user interface (100) of a manipulator program and to a method for navigation through a manipulator program, wherein the manipulator system (1) controlled by the manipulator program comprises at least one manipulator (30). The manipulator program comprises at least one set-down point (AP1 to AP5). The user interface (100) has a graphical program progress indicator (150) which indicates the current program progress of the manipulator program and the at least one set-down point (AP1 to AP5) of the manipulator program. The at least one set-down point (AP1 to AP5) indicated can be selected by a user, and the manipulator program is set up to control the manipulator system (1) in such a manner that the system assumes a system state assigned to the selected set-down point (AP1 to AP5) in response to the selection. The method comprises the steps of: providing a manipulator program; producing the graphical user interface; stopping the manipulator program; receiving a selection of a set-down point on the program progress indicator of the graphical user interface; and guiding the manipulator program to the selected set-down point, with the result that the manipulator program controls the manipulator system in such a manner that the system assumes the system state assigned to the selected set-down point. Such navigation may be advantageous, in particular, in the field of debugging, error correction and parameter correction or parameter optimization.

A programmable controller includes a parameter manager to manage a parameter including an operation mode setting indicating whether an operation mode of the programmable controller is an active mode or a debug mode, and a character string data outputter to output character string data based on a message output command included in a program in the programmable controller. The message output command includes a first argument specifying whether a command is to be executed when the operation mode is the active mode or to be executed when the operation mode is the debug mode. The character string data outputter outputs or does not output the character string data to a preset destination, based on a result of a comparison between the operation mode setting and the first argument.

It is disclosed a PLC Program analysis method where a program (PROG) is translated (TRANS) into a model (MOD) in a logical framework, from which properties (Prop) are determined. Said properties coupled with user specifications (IntProp) are verified by an automated solver (SMT). If contraposition of a property (Prop) is satisfiable, counter-examples (PROOF NOK) representative of model inputs and internal memory values is provided. Counter-examples (PROOF NOK) are translated into error initial configurations (IniConf) of said model. Execution of the model is simulated (EXE) with said model error initial configurations (IniConf), and error intermediary configurations (AST-IntConf) of said model simulation are recorded up to said property violation. Error initial and intermediary configurations (Lad-IniConf, Lad-IntConf) of said original program (PROG) are derived from error initial configurations (IniConf) of said model and error intermediary configurations (AST-IntConf) of said model simulation and displayed. An apparatus for executing said method is provided.

Disclosed systems and methods for monitoring an execution system of a programming logic controller (PLC), the method comprising: accessing, by a security module, the PLC execution system and dividing the code and data of the PLC execution system into a plurality of program modules; modifying, by the security module, data exchange interfaces of the program modules used for the interaction between the program modules and the resources of the operating system such that said interaction occurs through the security module, while a format of the data being exchanged complies with a format specified by the security module; and monitoring, by the security module, the execution of the PLC execution system, including monitoring the interaction of the program modules of the PLC execution system with each other and with the resources of the operating system.

Disclosed embodiments include a method of using a general-purpose microprocessor to debug a programmable logic controller. In some embodiments, the method includes: at a MPU of the PLC, backing up identification information and file information of an interrupt step of steps comprised in a user's program and substituting the interrupt step with an exceptional interrupt code to set the interrupt step for the debugging; and at the MPU of the PLC, interrupting the driving of the PLC at a step including the exceptional interrupt code in executing the user's program step by step while driving the PLC.