PackML: an industrial technical standard
10 December 2019
At the onset of a software standardisation project, Yellax is regularly asked whether an existing technical framework can be used as the starting point. This approach can offer several advantages for a planned standardisation project as the main areas for the work to be carried out are already defined within that framework.
PackML, an OMAC standard
PackML (Packaging Machine Language) is a framework of this type. PackML is an industrial technical standard for the control of machines. Originally conceived for the packaging industry, PackML is now also successfully applied in other industries. In machine construction industry for example.
PackML defines frameworks for communication with and control of machines. Newly developed machines can be tested based on these predefined frameworks and then reported operationally ready. This is an important advantage compared to well-known sequence-based schedules, such as Finite State Machines, Grafcet, Mealy & Moore Machines, Weihenstephan or a self-determined standard that many machine builders already use.
The reason for this is that defining your own framework has been found to be difficult in practice, due to an inability to anticipate all situations for future machines beforehand. The frameworks set by PackML provide guidance, both for the engineer and management.
Additional benefits of PackML
Furthermore, PackML simplifies communication with the customer. The customer can read the PackML documentation to get a feel for how his/her machine will work in general. Design choices can be better substantiated and the use of a predefined interface simplifies the task of integrating machines in machine lines.
This improves software maintainability, which is appreciated by the service engineers at a later stage.
The way in which the machines run also has benefits for the operators. Because the user-experience associated with the machines is the same throughout the factory, training operators is easier and more effective and operators can also be deployed more flexibly. This can contribute to greater safety in the production environment.
Further reasons why PackML is used:
- OPC UA Specification for communication with other and higher-level systems;
- The ability to easily and accurately obtain OEE data (Overall Equipment Effectiveness);
- Documentation is available;
- This contributes to safeguarding knowledge;
- New colleagues can be familiarised with their duties faster and deployed as a flexible resource.
Points to consider when using PackML
Obviously, a number of aspects must be considered when using PackML. The frameworks within PackML are usually defined for the current machines, because that is tangible. This means that the frameworks are not always suitable for subsequent machines.
Rules always change over time because the situation always changes. This is similar to manoeuvring in traffic. You cannot fully anticipate what situations will arise in the future. So we adapt the rules to the requirements of the situations at that specific time. This is why PackML frameworks also have to change as time passes. When this occurs, all the machines that were previously reported operationally ready must be tested again according to the new frameworks.
The PackML framework is broadly applicable by design and not all rules are relevant in each and every specific situation. This can sometimes result in overhead or unnecessary dead weight.
For example, part of the code included in the standard PackML framework may not have any function in a specific machine configuration. One possible option is to adapt the PLC code appropriately, i.e. simplify it so that only the functions that are in use remain.
From a financial point of view, this might be beneficial if a PLC with less working memory could be used for the project. Resulting in a lower purchase price.
In this situation, you obviously need to assess whether the man hours required for modifying the standard code are worthwhile compared to the price of a more expensive PLC.
A basic project for the PackML framework
Yellax has developed a basic project for the PackML framework. This can be useful when starting an implementation or standardisation trajectory.
We know from experience that customer-specific components generally need to be added to the basic project, however this does provide a starting point for development.
Modifying a basic project is often faster than rethinking things, as it encourages targeted discussion.
PackML knowledge-sharing session
Sharing knowledge breeds knowledge! With this in mind, Yellax regularly organises knowledge-sharing sessions on diverse topics in the field of industrial automation.
During an earlier power session on PackML, we discovered a strong need for more detailed analysis of this topic among our business relations.
So Yellax has decided to organise several knowledge-sharing sessions on this topic for interested system integrators and machine builders!
‘Why PackML? How can we best deploy it? What are the challenges in using PackML?’
Interested? We look forward to welcoming you at our office in IJsselstein!
For more information about the programme and free-of-charge registration, visit www.yellax.com/event.