Exploring OPC UA

Question

I believe that the OPC community here is one of the better ones and would like to understand from all of you on the following:

1. I would like to know if the OPC UA server is able to concurrently serve the same set of real time data to a client that is outside of the organisation?
2. Would high real time data loads create problems for OPC UA? I've read about Kepware/Matrikon as alternative solutions but are these common?
3. Are there ways to detect data alternation sent to the OPC server?
4. Would it be better to develop a custom client program that sits inside the organisation to assist as a 3rd party in providing audit and maintenance services to existing factories, or will it be better for it to sit outside (assuming with certificates)?
5. Apart from OPC, what are they other lesser used but legacy standards?

In advance, thank you very much

Answer 1

1. Yes. This really depends on your implementation and infrastructure. It is also easier to do with OPC UA than OPC DA (Classic).
2. OPC UA is a protocol. How much data your server can handle would depend on your implementation and infrastructure. There are many OPC servers that handle thousands of clients and millions of nodes.
3. What do you mean by "data alternation"? Your client can subscribe using data value or a server timestamp. This way, the client can get an update when the value changes or when the timestamp of the value changes even if the value stay's the same.
4. This depends on your business requirements. OPC UA is an open protocol, so in theory, any client that supports OPC UA would be able to connect to your server. In practice, this could be different and you may have to debug issues on your customer's clients.
5. There are many standards. Which one to use depends on your application and business requirements. Some you might consider are NATS, MQTT, gRPC, Modbus, etc.