A program in ladder logic, also called a ladder diagram, is similar to a schematic for a set of relay circuits. An argument that aided the initial adoption of ladder logic was that a wide variety of engineers and technicians would be able to understand and use it without much additional training, because of the resemblance to familiar hardware systems. (This argument has become less relevant given that most ladder logic programmers have a software background in more conventional programming languages, and in practice implementations of ladder logic have characteristics—such as sequential execution and support for control flow features—that make the analogy to hardware somewhat imprecise.) Ladder logic is widely used to program PLCs, where sequential control of a process or manufacturing operation is required. Ladder logic is useful for simple but critical control systems, or for reworking old hardwired relay circuits. As programmable logic controllers became more sophisticated it has also been used in very complex automation systems. (wikipedia)

Να δώσετε τα σύμβολα των πιο κάτω εντολών στον προγραμματισμό. Λογικής Κλίμακας (Ladder): α) Επαφή κανονικά ανοικτή β) Επαφή κανονικά κλειστή γ) Πηνίο ... (ΥΠΟΥΡΓΕΙΟ ΠΑΙΔΕΙΑΣ ΚΑ)