It's not enough to download and install the Servlink OPC Server. To use this application, you need to register it first. To do this, head over to the developer's official website. From there, log in using your account. If you don't have an account, press the Registration button to create one. After you access the customer area, you should be able to register the product, in order to properly connect to the Woodward EM Digital Gas Valve. All the additional information that you need is the Support area on the same site.
