> 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-structure-and-standard/selmo-technical-standard-and-structure/zones/zone-types.md).

# Zone types

### 📘 Zone types in the Selmo model

Zones are the smallest but decisive unit in a Selmo model.\
They connect the logical sequence with the real technology – i.e. with sensors, actuators and internal states.

Each zone describes exactly **a signal behavior** and is used uniquely in each SEQ.

***

#### 🔹 Zones in the context of the Selmo structure

Zones are located below the SEQ and serve as the interface between:

* **Process model (Logic Layer)**
* **Signal control (System Layer – Bit-Control)**
* **User interface (HMI texts, diagnostics)**
* **Safety behavior (CMZ, MXIC, Interlock)**

***

#### 🔄 Overview of zone types

| Type     | Description                                  | Application                          |
| -------- | -------------------------------------------- | ------------------------------------ |
| `Input`  | Input signal (sensor, button, safety signal) | Queries, conditions, state changes   |
| `Output` | Output signal (valve, lamp, actuator)        | Control, actions, positioning        |
| `In-Out` | Combination of output + feedback             | Actuator with feedback contact       |
| `Mem`    | Internal state logic (set, reset)            | Process marker, intermediate results |

***

#### 🧠 Typical examples

| Type   | Example          | Explanation                        |
| ------ | ---------------- | ---------------------------------- |
| Input  | `ZI_PartPresent` | Sensor detects inserted part       |
| Output | `ZC_ClampValve`  | Output controls clamping cylinder  |
| In-Out | `ZIO_SlideOut`   | Valve with end position sensor     |
| Mem    | `ZM_PartChecked` | Marker “part has been checked” set |

***

#### 🔐 Extensions per zone

Each zone can additionally be defined as:

* **CMZ zone** → permanently monitored safety signal
* **MXIC zone** → button for manual activation, with release condition
* **Bear-Check / Pair-Check** → plausibility or contradiction check

All these functions are **modeled, documented and testable** – without additional programming.

***

#### ⚙️ Behavior via Bit-Control

In **System Layer matrix** the behavior of the zone is defined per state:

| Symbol | Meaning                                                       |
| ------ | ------------------------------------------------------------- |
| `0`    | Zone is inactive                                              |
| `S`    | Zone is expected to be active (e.g. button, sensor, actuator) |
| `i`    | Interlock – zone must be correct, otherwise stop              |

***

#### ✅ Summary

Zones are:

* **the bridge between model and reality**
* **clearly typed** by signal behavior
* **fully documented and exportable**
* **central elements for safety, diagnostics and control**

📌 *Every real component of a machine is described uniquely in the Selmo model by a suitable zone – logical, verifiable and traceable.*


---

# 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-structure-and-standard/selmo-technical-standard-and-structure/zones/zone-types.md?ask=<question>&goal=<endgoal>
```

`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.