If you will be using the OPC client capabilities of the controls - you will need an OPC deployment license for that computer if you want to be able to communicate to OPC servers for more than 10 minutes at a time. Item Number License Type Product Price US$ Online Ordering Link 41266124 OPC client deployment (covers any base license) OEM/Site/Integrator/Consultant Unlimited OPC deployment license 695.00 IMPORTANT NOTE: An OPC Client license is ALSO required on the DEVELOPMENT computer. The OPC Client interface will maintain a connection to the OPC Server(s) for 15 minutes before timing out IF, and ONLY IF you do NOT have a valid OPC Client Runtime license installed on that computer.