> For the complete documentation index, see [llms.txt](https://infosys.selmotech.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://infosys.selmotech.com/selmo-solution/selmo-solution-en/selmo-templates-and-tools/technical-manual-chapter.md). # πŸ“˜ Technical manual chapter ### **Selmo operating and control concept – structure, function and safety** *(according to ISO/IEC 82079-1: Information structure for technical instructions)* #### **1. Purpose of the document** This chapter describes the machine's operating and control concept, whose control system is based on the **Selmo method (Sequence Logic Modelling)** It serves to explain the logical mode of operation, the safety mechanisms and the interaction between operator, machine and control. *** #### **2. Target audience** This document is intended for: * machine operators and plant operators, * maintenance personnel and service technicians, * inspectors, auditors and CE officers, * integrators and software engineers working with Selmo Studio. *** #### **3. Overview of the system principle** The machine control follows the principle of **deterministic sequence control (Selmo SEQ)**.\ This means: * The control works with **states** instead of individual commands. * At any time **only one state active.** * Transition to the next state occurs **only**, when all defined conditions are met. This structure ensures reproducible, traceable and safe behavior of the machine. *** #### **4. Control architecture** **4.1 Structure of the layers** The control system is hierarchically divided into: 1. **Plant (entire system)**\ – the logical overall structure of the machine. 2. **Hardware zones (HWZ)**\ – physical areas with independent control logic (e.g. stations or modules). 3. **Sequences (SEQ)**\ – sequence controls within an HWZ. 4. **Zones (Zone Types)**\ – logical function blocks that map real signals or virtual functions. **4.2 Sequence Engine** The sequence engine is the process and clock generator.\ It continuously checks the three core conditions: | Input quantity | Meaning | | ------------------------------- | ----------------------------- | | **AR (Auto Release)** | Automatic release active | | **Β¬I (No Interlock)** | no safety violation | | **Ξ£S (Sum of Sequence Checks)** | all ongoing actions completed | Only when **AR = 1 ∧ Β¬I ∧ Ξ£S = 0**, the state change occurs.\ This ensures that the sequence is only continued in a safe state. *** #### **5. Zone level and behavior** **5.1 Definition** Zones are standardized switching elements that bundle actions and feedback.\ They represent the connection between logic and physics. **5.2 Zone types** | Type | Description | Example | | ----------- | ----------------- | --------------------------- | | **IN** | Input signal | Start button, sensor | | **OUT** | Output signal | Lamp, valve | | **IN\_OUT** | Action + feedback | Cylinder, axis, calculation | | **MEM** | Memory zone | Software status, parameter | **5.3 Operants (Bit-Control)** Each zone has an assigned function in every state: | Operant | Meaning | Effect | | ---------------------- | --------------------- | ------------------------------- | | **S (Sequence Check)** | Action active | waiting for feedback | | **I (Interlock)** | Safety monitoring | stops sequence in case of error | | **M (Monitoring)** | Diagnostic monitoring | reports notice without stop | | **0 (Don’t Care)** | inactive | no function in this state | This assignment is defined in Selmo Studio in the **System Layer** defined. *** #### **6. Safety functions** The system contains several standardized safety mechanisms: 1. **Interlock function** – detects safety violations and stops the sequence. 2. **PairCheck** – monitors contradictory feedback (e.g. cylinder front/back). 3. **MXIC (Manual Cross Interlock)** – prevents unsafe hand movements. 4. **Monitoring (M)** – provides diagnostic messages without interrupting the process. All functions are an integral part of the standard; no additional programming required. *** #### **7. Operation via the HMI** The user interface shows: * the active state, * the active zones with color coding, * plain-text HMI messages, * error and diagnostic lists. **Color coding:** * Green = AutoRelease * Red = Interlock * Yellow = Warning * Gray = Manual Mode *** #### **8. Behavior in case of malfunctions** In case of errors the system reacts automatically: 1. The sequence stops. 2. The affected zone is marked in red. 3. An error message with cause appears on the HMI. 4. After error correction and release (AR = 1) the sequence continues. This ensures that every fault is clearly localized and handled safely. *** #### **9. Documentation and traceability** The Selmo model documents itself: * Every state, every zone and every operand are stored in the system. * HMI texts and diagnostics are generated automatically. * Changes are versionable and auditable. This allows the control to meet the requirements for traceability and CE conformity. *** #### **10. Summary** The Selmo concept defines a clear, traceable and safe control structure: * formal state description (deterministic), * standardized zone logic, * integrated safety functions, * automatic diagnostics and documentation. For operators this means: transparent processes, clear messages, safe operation.\ For the manufacturer: standards-compliant documentation and uniform quality standard. *** #### **11. Reference** This concept is based on the Selmo standard according to the development guidelines of\ **Selmo Technology GmbH – Sequence Logic Modelling System**. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://infosys.selmotech.com/selmo-solution/selmo-solution-en/selmo-templates-and-tools/technical-manual-chapter.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.