6 Operation of the machine (user view)

"This chapter describes how the previously defined model acts – not what is modeled."

6. Operation of the machine

This chapter describes, how a modeled machine is operated. It is not about user interfaces or specific buttons, but about the fundamental interaction of model, operator and system.

Operation is in Selmo no additional logic layer, but a Perspective on the same model.

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6.1 Basic principle of operation

A central principle in Selmo is:

Operation does not change the logic. It only changes who has influence on the model.

This means:

• Sequences remain unchanged

• States remain valid

• Bit control remains active

• Monitoring remains effective

• CMZ operates independently of the operating mode

There are:

• no second sequence definition

• no bypass

• no special code for operation

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Shared state space

Regardless of the operating mode, the following applies:

• every sequence is always in exactly one state

• this state defines expectations and monitoring

• Deviations are unambiguously assessable

Manual and automatic operation work in the same state space.

Manual operation is not a parallel world, but targeted interaction within a valid state.

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Roles in operation

Operation clearly distributes responsibility:

• System

  • evaluates the model state

  • monitors conditions

  • responds deterministically

• Operator

  • influences zones purposefully

  • establishes states

  • does not make logic decisions

• hardware zone

  • provides operating modes

  • manages automatic releases

  • coordinates starts and stops

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Automatic and manual operation – classification

Selmo distinguishes two operating modes:

• Automatic operation

  • the system drives the sequence

  • state transitions occur automatically

  • Monitoring reacts immediately to deviations

• Manual operation

  • the operator influences zones manually

  • The goal is the fulfillment of state conditions

  • Monitoring remains fully active

Both operating modes:

• use the same model

• are subject to the same rules

• produce the same diagnostics

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Safety in operation

Safety-relevant mechanisms take effect always, regardless of operation:

• Interlocks (i) protect the sequence

• CMZ protects system integrity

• MXIC protects against unauthorized manual actions

There are:

• no “service mode” without monitoring

• no manual operation without safety

• no exception to the model logic

Operation is not a safety concept – Safety is anchored in the model.

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Structure of this chapter

Chapter 6 is divided into the following parts:

6.1 Basic principle Operation

→ shared state space → operation ≠ logic

6.2 Automatic operation

→ system-driven sequence → error responses → diagnostic behavior

6.3 Manual operation

→ state-by-state work → visual feedback → safe positioning

6.4 MXIC – Manual Cross Interlock

→ protection logic for manual actions → diagnosis instead of movement

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Transition to the details

The following sections describe:

• how automatic operation works concretely

• how manual operation works safely

• how manual actions are limited

Operation makes the model usable – without changing it.