Nowadays any software functionality is required to be delivered faster and with minimal cost while maintaining the expected quality. This applies to any software and also to process automation applications. These critical applications must be extensively tested to validate requirements and ensure smooth execution 24/7 in industrial plants such as manufacturing, nuclear plants, pharmaceuticals, cooling systems, etc.
In general, it is acceptable to divide the tests according to their level of specificity in:
(1) unit tests, where a specific section of code is tested separately,
(2) integration tests, where all individual units come together to be globally verified and
(3) system tests where the complete system is tested as a complete application.
At present, the tests are applied to process control applications such as black box function tests or modules in combination with input simulations and visualization of the results by the manual tester. The test cases are created manually from the requirements or specifications by the developer and basically the tests are considered as another development activity. Following the industrial automation standard ISA-62381, the tests of the applications of control of processes are realized in two main stages: Tests of acceptance of factory and of site, FAT and SAT, respectively. The difference is whether the tests are done in the factory or in the actual plant. Automated testing allows better implementation of repetitive or tedious tasks and can hardly be achieved with a manual tester. These tests are a complement and not a replacement for hand-made testing procedures, in fact not all tests are easily automated. The analytical skills of the manual tester can hardly be replaced and these testers are often necessary in interpreting the test results. Therefore, manual and automated tests are not independent, but complement each other. Formal methods, in this context, are mathematical techniques for the specification, development and verification of software and hardware systems. Applied to the programming code, formal methods provide a precise semantics of a program. With this formalization we can prove that the program is correct, which means that it complies with the user's specifications. Taking into account that other testing mechanisms can never guarantee error-free applications this technique seems to be a solution, however the complexity is an obvious drawback. The article describes the environment in which the test procedures should be applied, with test methods focused primarily on automated test mechanisms and formal methods. Finally, a summary of the results and the analysis of the advantages and disadvantages of the application of these mechanisms is presented.
CNC Cutting Machine
We are among the leading manufacturers of top quality CNC cutting machine. Plasma cutting is a process that is used to cut stainless steel, mild steel and aluminum of different thicknesses using a plasma torch. In this process, an inert gas is blown at high speed out of a nozzle, at the same time an electric arc is formed through that gas from the nozzle to the surface being cut, the plasma moves fast enough to blow the metal Fused away from the cut.
