1. What are the Industry 4.0 communication guidelines based on OPC UA?
There are various Industry 4.0 communication guidelines based on OPC UA. One of them is the 3 steps for gradual migration to OPC UA communication.
- First step is to enable condition monitoring systems to access data from machines
- Second migration step is to use plug and work standardized models
- Third step is role-based authorization of OPC UA
- The migration process needs to be standardized and secure
2. Is OPC a game-changing element of Industry 4.0?
Yes, OPC is a game-changing element of the fourth industrial revolution. This technology allows flexible and secure use of data across IT and OT boundaries.
3. What is the key difference between OPC DA and OPC UA?
OPC DA works on Microsoft DCOM based technology which can work only in Windows. On the other hand, OPC UA works on address ports and hence it is platform independent, which means it works on different OS flavours like Windows, Linux and Micro-Controller (RTOS).
4. How are the security certificates exchanged between a client and the server?
“Certificates are a way for clients to establish a secure connection with servers. Whenever a client tries to connect to the OPC UA server, it will first verify whether the client certificate is available in its server trusted folder path. If not, the client certificate will be moved to the server rejected folder path. The user will have to manually move the certificate to the trusted folder path to establish the connection between client and the server.”
5. Does the OPC UA require TUV approval for communicating across SIL3 systems?
“The OPC UA Safety working group has published Release 1.00 of the specification for the interoperable communication standard for functional safety – OPC UA Safety “Part 15 OPC UA Core Specification”. OPC UA Safety is based on the black channel principle and currently addresses controller-to-controller communication using OPC UA clients/servers.
Source: https://opcconnect.opcfoundation.org/2020/03/specification-for-opc-ua-safety-release-1-00-completed/ The certification guide lines are not yet finalized and the specification scope is up to SIL level 4. “
6. What is the maximum number of clients that can be connected to OPC DA and OPC UA servers?
The OPC DA and OPC UA architecture doesn’t place a limit on the number of maximum client connections. However, it depends on system configuration of your application.
7. How to change the server configuration be changed from OPC DA to OPC UA?
You need to have a converter OPC UA to access and convert the OPC Classic DA data, so that your OPC Client can connect and monitor that information.
8. Can OPC UA Server/Client connect directly to any database for exchanging data?
Technically yes. The OPC UA server/client can directly connect to any database for data exchange. However, it largely depends on type of database that you select. The OPC UA server/client can be customized as per your database schema to create specific information models.
9. How is OPC UA is taking part in the OPAF?
The O-PAS standard from the OPAF is based on OPC UA standard. So, eventually if and when OPAF brings forth any use cases that can’t be handled with the existing OPC UA Specifications, there may be a need for coordinated effort to handle such cases between both organizations. Any member companies who are in both organizations will play a key role in such scenarios.
10. Which is the best OPC Simulator available in the market? Can the simulation history be viewed?
“The market for OPC UA simulators is flooded with OEMs as well as third party vendors delivering COTS products or framework based solutions. Each offer their own variations of the OPC UA simulators that can be customized to meet your specific requirements.
If you can share your requirements for OPC UA simulations, Utthunga’s uOPC Simulate framework can help you in developing applications for simulation of communication protocols, field devices, control systems, process flow and network traffic. Many of our clients including ABB have leveraged our expertise on working for different simulators to satisfy their business needs. “
11. How to implement redundancy and high availability in the OPC UA network?
Any application which uses address ports for OPC UA server to communicate across the firewall, will have its ACL/rules configured for allowing both inbound and outbound access.
12. Does the alarm and conditions data keep stored in the OPC UA Server even when the connection breaks down?
No. The A&E data will not be persistent in the OPC UA server if the connection is severed.
13. What is the difference between OPC UA, OPC DA, and OPC A&E?
“Thank you for participating in our OPC UA Inside Out Webinar. Since this is the Part 1 of ongoing webinar series on OPC UA, we would like you to attend all of our remaining webinars which will lay the foundation for understanding the overall OPC architecture, its different variations (UA, DA, AE and HDA) and the supporting specifications/standards. As a basic difference, OPC DA works on Microsoft DCOM based technology which can work only in Windows. OPC UA on the other hand works on address ports and hence it is a platform independent which can work on both Windows, Linux and Micro-Controller (RTOS). ”
14. Are IoT and OPC UA redundant?
OPC UA is more on a standard way of data exchange but IOT covers the larger scope of bringing data to a central place and analysing them using various analytical methods plus the visualisation and reporting. We can help you understand both IoT and OPC UA technologies, its various pros and cons with respect to your specific requirements.
15. How does OPC enable data acquisition from the older versions of PLCs and controllers?
This is a challenge. The data acquisition from these legacy PLCS and other controllers must be handled on a case-by-case basis with some level of custom solutions. There are multiple options available for the end-users.
- You can bring the entire PLC to common communication protocol, say Modbus TCP and have the edge device supporting Modbus TCP as its downlink layer.
- Use the Edge Device, which has support for the PLC at the downlink layer.