Many TSN standards and overlaid protocols are currently still in the standardization phase. Nevertheless, work on prototypes is in full swing across companies. This approach was rather untypical in the past, especially in the automation industry, but is unavoidable with TSN. The reason for this is that, on the one hand, TSN represents a central basic technology for the digitalization of production and, in this role, must meet both broad acceptance and all the requirements of the various industries; on the other hand, the complexity of the transformation from separate IT and OT systems and the associated communication technology to convergent systems and networks exceeds what has been known to date. Therefore, in addition to standardization, experimental implementations, early prototypes and well-founded investigations of the existing results and discussed concepts are always required.

Pre-competitive prototyping

Supporting prototyping activities at this stage is a not inconsiderable effort for the companies involved. And yet, it is precisely this prototyping that benefits both the technology itself and the companies involved:

- Support for standard development: many companies are involved in standardization committees. Testing, validating and optimizing the approaches discussed there requires prototyping, which can usually be done more efficiently in a joint effort.

- Activation of the ecosystem: In order for TSN and the convergent systems based on it to make the desired contribution to digitalization, this ecosystem must be as widespread as possible. Sufficient infrastructure must be available and as many end devices as possible must support the relevant standards. Dependence on the ecosystem as a whole is a direct motivation for everyone to support it.

- Interoperability: In addition to the spread of the technology, smooth interoperability in particular is a prerequisite for a functioning ecosystem.

- Product development: A very pragmatic motivation for getting involved in early prototyping is the expected head start in future products.

- Innovation: Many recognize the relevance and potential of digitalization, but are not yet sure about their own strategy. An early exchange and technical insight can promote innovation and avoid bad investments.

'Neutral floor' in the testbed

A plugfest of the TSN Testbed at ISW: In addition to testing, various aspects of TSN will be discussed and practiced.

© ISW

In order to enable early prototyping and testing across different industries and competitors, an appropriate framework is required. Various testbeds have been established here over the last few years, such as the IIC TSN Testbed, which is managed and hosted by the ISW at the University of Stuttgart.

The testbed offers a neutral location where companies can work across manufacturers in an organized framework without any obligations or financial hurdles. The testbed covers various aspects to enable efficient prototyping. In addition to a continuous virtual exchange, there are usually three plugfests per year at the ISW. The participants meet here for several days - in addition, the US instance of the testbed organizes further plugfests.
Various activities are pursued as part of these plugfests. In addition to the testing itself, there are discussions on various aspects of TSN. The testbed covers TSN as a whole and is not limited to individual applications or overlapping protocols. Nevertheless, topics relating to the OPC UA FLC initiative are currently playing a major role and are therefore also given special consideration.

The testing of TSN

The 'Interoperability Rack Setup' ensures continuous operation of the devices and enables remote access for the participants.

© ISW

Testing is at the heart of the plugfests. However, the activities that take place here differ significantly in terms of the motivation behind them, the test objectives and the specific procedure:

- Proof of concept: validation of a standard, concept or implementation at an early stage

- TSN standards: Verification of conformity to the standards

- Interoperability: cross-manufacturer compatibility

Testing in the early prototype stage usually takes place bidirectionally or in small groups between interested participants, who are often also involved in standardization. The testbed provides the necessary infrastructure, a sufficient number of end devices and measurement options. (Sufficient) conformity with the basic standards for time synchronization and traffic scheduling is a prerequisite for any interoperability testing. To ensure this, a rudimentary check of the devices is carried out in cooperation with test tool manufacturers (base testing).

In close contact with the competition - A commentary