PROFINET certification can be an intimidating process, but it doesn’t have to be. Knowing what you’re getting into before you complete the test application not only sets expectations, but it also puts you in a position to streamline the process.
Step 1: Choose a Test Lab
PI Test Labs operate as independent and accredited institutions. They aren’t part of the official PI org chart, but they work closely with PI to perform certification work. PI maintains a list of all test labs worldwide that you can use to find a test lab that offers the services you need. Each lab maintains separate pricing structures, lead times, turn times, etc (ours are available on our website). So when you’re going to apply for a test, you may want to obtain estimates from several labs before issuing a PO for the test services.
Step 2: Schedule Test
You should get in touch with your PI Test Lab when your project design is still fluid but is getting close to feature-complete. The lead time required to schedule a certification test varies between test labs and with the season (summer and fall seem to be the busy season at the PIC). In general lead time is usually between two to six weeks. Turn times are heavily dependent on the customer. A test lab can’t issue a positive test report until a Device or Controller is totally compliant with the PROFINET specification. Any issues found during certification must be addressed.
Step 3: Validation and Verification
PI has published a test bundle that includes all of the software used to test devices in the certification test lab, and it’s available to PI members for free. This test bundle contains all of the tools used during the certification test and can provide a good sanity check to make sure your PROFINET device is ready for the lab. However, it’s not an autonomous platform. There’s a lot of analysis that goes into analyzing the test results, and finding the root cause of issues can be a daunting task. You should ask your technology provider if they provide any kind of pre-certification testing. Alternatively, your test lab can provide pre-test services or even training to help you understand how your technology solution works and what might need to be improved prior to certification.
Step 4: Work with the Test Lab
At the PIC, experience has shown that small teams with a good relationship with their technology provider move through the lab much faster than large teams that don’t have a PROFINET expert in their corner. This is especially true for software stack implementations of PROFINET, where a host of protocols have to work together seamlessly to meet the certification requirements. Once your test starts, anticipate two or three days with little or no feedback from the test lab – it takes that long to get a complete picture of a device’s weaknesses. Once the lab’s done with their initial assessment of your device, they’ll deliver a list of required changes to you.
That’s when timely responses are critical. The lab may accept issue fixes piecemeal or may require you to address all open issues at once. In either case, you must coordinate with the lab to schedule a re-test for your device. If you miss your scheduled re-test date, you’ll have to schedule again. With each re-test, the lab will add whatever lead time is necessary for it to process the current work queue and get you back into the mix.
Step 5: Certification
The certification process isn’t done when the test lab issues a positive test report. A test report isn’t a certificate, and you need to apply for one with the PI Certification Office. However, that’s (mostly) a paperwork formality – the hard work of development and testing is over, and you can look forward to releasing the product.