Lost in Translation? SELMO – ONE digital PLC language!
For companies to benefit from all the advantages of digitization and to be at the forefront of industry 4.0 or block chain, they must solve a fundamental problem.
How do we manage to get faultless PLCs up and running quickly and in a functionally stable manner? A uniform PLC language provides one answer.
The traditional view of digitization in mechanical engineering is usually divided into three clearly defined areas:
First, the mechanical eye dominates, then the electrical engineer follows, and finally, the findings from mechanical and electrical engineering are digitized and translated into a software requirement. During this translation, there are always transmission errors and the “lost in translation” effect:
Customers and experts say similar things, but mean different things, which may be interpreted differently by the software development department. However, since the software is supposed to control all processes and guarantee smooth operation, there should be no misunderstanding or translation errors.
If a single bit is tipped, the entire operation comes to a standstill. The software as the steering wheel of automation in operation should therefore form the basis for engineering – not the other way around. This change of perspective eliminates two further sources of error:
1) Firstly, software requirements based on structural and electrical engineering specifications must be programmed manually or at least adapted manually. In practice, a completely error-free code for complex requirements right from the start is the exception rather than the rule. Finding errors costs a lot of time and money – and often even jeopardizes the success of implementation. SELMO ensures that the sequence, the step chains and the core of an automated system are generated without errors. Provided that the processing logic is correct in advance.
2) Secondly, it is mathematically impossible for humans to anticipate and program all possible signal states of a state machine.
SELMO is first and foremost a uniform PLC standard that speaks the “universal” digital language of automation. Every machine is represented in its entirety, every single bit of a machine status is visible – throughout the entire process. In addition, SELMO is an innovative method that enables integrated engineering and real digitalization of machine processes. With it, all departments come together at one “digital” table. They first create process-relevant machine models, which are then automatically generated. The SELMO algorithm as a novel method becomes the blueprint for integrated SELMO engineering, in which all views of the machine are united by a common basis. This not only lowers costs in the automation process but also reduces error rates and the effort required to operate the machine.
The generally applicable SELMO standard eliminates high training and development costs. As a framework, it works according to a simple logic: each machine is based on the same generic basic functions and structures – each of which is run in a specific sequence. It is like a digital book in which many things are written down. Only a few blank pages need to be filled for the individual process, for which the plant operator is an expert anyway. This allows each process to be digitally modelled and adapted to the requirements of the plant operator – without having to renegotiate the basic specifications each time.
Because the standard methodology of sequential logical modelling is based on the production process and not on individual assemblies, SELMO creates automation “from a single source” that is open to change. The premise is Digital first! All trades always have the same digital image in mind right from the start of the project. Implementers can use the “Modeller” tool to digitally model every individual process, display it clearly and implement it in both old and new (state) machines. Process and system requirements are modelled via four layers – step by step and bit by bit. Flexibility is achieved through parameters and the freely configurable display through generated data points. Because logic and function are separated, changes can be made quickly to the model. This not only creates a completely transparent automation logic. SELMO is at the same time a digital functional and performance specification that makes everyday operation much easier.
The SELMO technique generates the stable PLC code from the model and gives users and converters control over every bit. The standard is maintained because it is algorithmically “translated” instead of manually programmed. A PLC and HMI code generator (“Creator” Tool) ensures this uniformity and fast implementation in programming. Data points for the display layer can be freely designed, as can the sequence control. The PLC code can be checked in CAD early on during 3D modeling. Every bit can be validated. With the SELMO Toolbox (Modeler, Creator) the digital twin can be ideally depicted and also virtually put into operation. This makes real commissioning safer and easier.
SELMO makes the software a technology leader that integrates and connects everyone. Machines and plants run with stable functions and can be operated by all employees. New processes can be integrated flexibly and seamlessly, old processes can be optimized and the entire system can be modernized cost-effectively. Thus, the path to automation via the SELMO software created at an early stage offers many advantages at a relatively low cost. Only ten to twenty percent of the usual investment sum for machine development falls on software development. The PLC is available and can be checked before the actual machine is built.