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PLC_programming - THE STEP7 PROGRAMMING LANGUAGE STEP 7 is...

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1 THE STEP7 PROGRAMMING LANGUAGE STEP 7 is the standard software package used for configuring and programming SIMATIC programmable logic controllers. It is part of the SIMATIC industry software. Basic algorithm for an automation process: Programs in a CPU In a CPU, two different programs are always executing: The operating system The user program. Operating System Every CPU has an operating system that organizes all the functions and sequences of the CPU that are not associated with a specific control task. The tasks of the operating system include the following: Handling a warm restart and hot restart Updating the process image table of the inputs and outputting the process image table of the outputs Calling the user program Detecting interrupts and calling the interrupt OBs Detecting and dealing with errors Managing the memory areas Communicating with programming devices and other communications partners If you change operating system parameters (the operating system default settings), you can influence the activities of the CPU in certain areas. User Program You yourself must create the user program and download it to the CPU. This contains all the functions required to process your specific automation task. The tasks of the user program include the following: Specifying the conditions for a warm restart and hot restart on the CPU (for example, initializing signals with a particular value) Processing process data (for example, logically combining binary signals, reading in and evaluating analog signals, specifying binary signals for output, outputting analog values)
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