1. Structuring the system
Important consideration in advance: What is the system structure?
The existing or new system is structured in a simple way, whereby the structural elements can be applied universally to any system.
Criteria for structuring:
- Plant: Entire system - plant - machine
- Hardware zone (HWZ): Plant zone, often also defined as protection zone or operating mode zone, manual and automatic operating modes are defined in this zone.
- Sequence: Is the smallest logical unit in a hardware zone and defines individual stations or logical sequences and is the central element of Selmo
The real system and the logical programme are structured in this way and are defined in the Selmo Standard.
Here are some helpful considerations::
- Assemblies - are they independent?
- Is it an advantage if an assembly is independent?
- Is it necessary that it can be controlled manually?
- Are different safety areas necessary?
2. Process and behaviour analysis
Important considerations up front: What requirements and process steps are necessary?
This step is critical and will further develop and possibly change the structure. It is not about the programming itself, but about the careful consideration of the the desired behavior of the system. This step defines requirements, usability and process-critical limits.
It is often sufficient to first determine that processes such as conveying, drilling and heating are taken into account. It is also decided which processing steps are possible. The requirements must be clear and detailed.
This step differs significantly depending on whether it is an existing system or a newly developed system.
Notes on Considerations:
- Processes: What happens when and with what dependencies
- Material flow: Material supply and removal
- What process steps do I want to monitor or need to verify?
- Determine the parameters
The aim is to formulate and understand the process, capture the dependencies and parameters, and analyze the behavior.
3. Technology analysis
Important consideration in advance: What technology is required to achieve the desired behavior?
Once the process steps and requirements have been defined, the appropriate technology can be selected and analyzed. For existing systems, existing technologies are recorded and evaluated. For new systems, the technology can be freely selected and defined.
Key Questions:
- What technologies are needed to achieve the desired behavior?
- Is the existing technology capable of meeting the requirements?
- Are there predefined components that need to be used?
- What type of target control is required?
Objectives:
- List all relevant technologies
- Evaluate and assign technology
- Determine development requirements for existing functionality
- Understand and apply the selected technologies
Criteria:
- Interfaces
- Verify usability of existing sensors and actuators
- Where do I need sensors and which ones to capture the process and behaviour?
- Where do I need which actuators to control the process and behaviour?
4. Functional analysis
Important consideration in advance: Which functions are essential for seamless operation?
Every system has both standard and specialized functions. Often, there are specific requirements for process behaviour, such as calculations, filters, ramps, etc., which can lead to additional functionality. The analysis is intended to enhance understanding and initiate solutions early on.
Objective: The creation of a list of all functions, the provision of function descriptions for users and operators, and the clarification of possible solutions using standard functions are essential.