The OPC Foundation has organized Interoperability Workshops (IOPs) for more than 20 years. The purpose of such workshops is the validation of interoperability between products provided by different vendors. This is an important step to prepare for formal certification but it is also a valuable addition to the testing process. Certification can only emulate the diverse product-specific characteristics and behaviors to some extent. It cannot provide the full range that an IOP provides.
Besides achieving interoperability, IOPs also offer
- An opportunity “to network”; i.e. become familiar with experts of other companies and exchange contact information.
- The chance to clarify ambiguities in the OPC standard in discussions with other experts or even representatives of the OPC Foundation if available.
- An opportunity to get organizational and technical news from the OPC Foundation.
Interoperability testing can be organized in many ways. This page describes rules and requirements for workshops endorsed by the OPC Foundation.
Key Data for OPC-endorsed Interoperability Workshops
Participation needs to be open to all OPC members (excluding Logo members).
It should include more than 10 and up to 40/50 products. More products require a longer workshop duration. As a rule of thumb testing of 10 to 15 products will require 3 days, while 30 or more products will require a full week.
The test facility (room) needs to be well equipped with tables, power supply, and a separate network. The room shall be lockable overnight.
The host needs to provide experienced network staff to set up and maintain an Ethernet network with sufficient switches (ports) for 10/100/1000 Mbit. The host also needs to ensure that enough 10Base-T cables are available. A minimum of two cables per participant shall be assumed. The network has to have a DHCP server available and the ability to assign fixed IP address to some nodes. Availability of NTP source is also recommended.
The network has to be connected to the internet or a separate network with internet connection needs to be available because participants have to enter test result data in an online database.
The host needs to ensure the accessibility of an OPC UA Global Discovery Server with a certificate authority (CA). If PubSub testing is part of the IOP, a Key Server shall also be provided.
At the bottom of this page are some pictures to illustrate such a setup.
Different guideline might apply for an information model specific IOP, but any changes shall be well documented, (eg every brings there own network cable or a PTP time source is being provided)
Required Experience and Expertise for OPC UA Technology and Tools
Because the IOP Workshops are held in the name of the OPC Foundation, the OPC Foundation also mandate a certain level of practical experience. This is required to keep the quality of the IOP Workshops at the expected high level.
The host needs to provide experts in OPC UA technology and staff with intimate knowledge of the testing, tools and processes at an IOP Workshop. Examples include having knowledge of how to operate the IOP Workshop application and how to create and distribute application instance certificates for the participating OPC UA applications.
In order to achieve this minimum level of experience the workshop organizer (person not company) is required to have attended 3 IOP Workshops as tester. It is also recommended that they request training in the use of the IOP Application and application instance certificate process during one of the IOPs. Alternatively, the OPC Foundation will provide a list of names if the host needs to hire such experts.
Basic Sequence of Steps
Before an IOP Workshop is officially scheduled, it needs to be coordinated with the OPC Foundation to ensure no overlapping events. After the workshop is scheduled, an OPC Foundation officer (see below for relevant contacts) will create the event. The event announcement and the registrations happen by means of the OPC Foundation event page.
The host will provide:
- Start and end time
- Contact information
- A registration limit (e.g. max 40 participants)
- The exact address of the event location
- A list of recommended accommodations
A registration limit can be defined (e.g. max 40 participants).
A registration fee can be defined which will be collected by the OPC Foundation administration office. The registration will be confirmed after the payment for the fee has been received. The usage of these fees needs to be defined before the event is announced and may include the payment of the expert services, event location fees (room rental) and lunch/beverages for the participants. An IOP Workshop is intended to be a nonprofit event and the fee shall only cover the costs of the event. Hosting staff including experts will also have to register but are typically exempted from the fee.
Approximately one week before the event, the host shall provide all participants final instructions, which might include instructions on how to enter the building, who to contact in case of any issues.
External Organization IOPs
External organizations or groups like joint working groups which are planning a separate IOP Workshop for their group can ask to have their event listed as external IOP Workshop so it is visible to OPC Foundation members. The request shall include the information listed above. These IOP Workshops are required to be open to all non-logo Members of the OPC Foundation. They may have other requirement on both infrastructure or attendees, but these shall be clearly described in the description of the IOP (e.g., predefined information model or specific APL network cables). This type of IOP might also have different disclosure requirements, such all attending companies will be listed, but again this need to be clearly defined in the IOP description
The Test Week
IOPs are informal. There are no requirements to pass a certain number of tests. The detailed results shall not be published by the host or one of the attendees. Only that a company attended maybe published and only by the attendee. I.e. a company may list that they attended a specific IOP.
Participants start with network configuration, moderated by the host. This will be done step-by-step with on-screen instructions. After successful configuration all devices will be part of the test network and have an application instance certificate issued by the CA used for this IOP Workshop.
Next, the participants will be instructed about infrastructure and test procedure:
- All Servers have to be specified by means of a Web-based entry-form (general properties, supported optional features, supported Variables /Conditions …). This data will go into the test database and will be available for the clients as test data. This form is available before the IOP and it is recommended that server vendors populate this information prior to the IOP.
- Clients will also use Web-based entry-forms to find available servers, view their properties, select them for testing, fill in test results, etc.
Participants are asked to specify their products online the week before the workshop in order to have more time for testing during the workshop.
The remaining days will be available for general testing. Every client has to perform an IOP test with every server of different vendors. Web-based forms will show the status with respect to available servers and clients.
Dependent on emerging issues we recommend to calculate minimum one hour but up to 2 or 3 hours for a test combination.
Each client vendor has to enter the test results for each tested server in a web-based form which will save the results in the online database. Any faults or failures discovered by a client, should be discussed with the Server vendors.
The database will be available to all participants until the end of the workshop. This database is hosted by the OPC Foundation and keeps the data confidential.
Besides the Testing
We have found that the attendees of the IOP Workshops usually get along with each other very well. Nevertheless, one evening event like an organized dinner open to all participants is always appreciated and heavily used by all participants.