Which are the limitations of the pi connectors over the pi interface ? how exactly the desired data is recognized by/via pi connector from is data source and transmitted to destination ?
There are many differences between PI Connectors and PI Interfaces.
1 PI Connectors can create AF Hierarchy which cannot be done by PI Interfaces. (This is not limitation though)
2 PI Connectors automatically create PI Points and basically users could not choose which tags do they want.
3 PI Interfaces support failover configuration (high availability), however only a few connectors support failover configuration. (Maybe PI OPC UA Connector supports failover configuration.)
Current development team in OSIsoft is focusing on Connector than old interfaces. So I believe more and more new connectors will be developed for new devices.
Product Roadmap shows old interfaces and a lot of connectors in the Interfaces & Connectors section.
Thank you Kenji Hashimoto for your response.
Your questions would be much better answered if you would specify what connector / data source you are considering since the technology is different depending on the data source.
I do want to touch on the second point that Kenji Hashimoto made. Connectors do come with an ability to decide what tag to bring in from the data source. Each connector has a slightly different process to do so, but it is generally done by some sort of filter file or using regular expressions.
Some protocols are also only supported in the connectors (OPC UA, REST endpoint for UFL, Modbus Cisco Router, and a lot more and even more to come). Generally, if you have the option between the two, I think that connectors are a better implementation for a new data source that is not already in PI, since it is configuration light and the future enhancement / updates will be focused on connectors. If you already have a data source in PI, then it is worthwhile to get some more details on the specific data source to see if it is a good idea to migrate to using PI Connectors.
Thank you Gabriel Michaud-Verreault for your responses, am interested the limitations of PI Connectors used for PI OPC UA?
First off, if you want to directly connect to an OPC UA server, you will need to use the PI Connector for OPC UA since we do not have an interface for the OPC UA protocol. If you were to use an interface, you would need to use an OPCUA to OPCDA wrapper and then connect the PI Interface for OPC DA to the OPCDA wrapper. That would add a layer to manage.
The main differences would be the following:
The connector will automatically create an AF Structure / Elements / Attributes for you, but at the time of writing, the tag names cannot be easily changed. The configuration for PI Connectors are significantly easier to decide what data item to bring in vs the manual configuration you would have to do in the interface. Also, if you can connect directly with OPCUA, you do not have to deal to DCOM configuration. OPCUA authentication is significantly more secured and the data can be encrypted.
The only downsides I can think of right now, (keeping in mind that some of these things are actively being developed), is that if many objects in your OPC UA server share the same template, you cannot bring only some of the objects unless you move them to a separate folder. The other one would be that PI Connectors do not currently have a good way to be monitored healthwise as they do not have health points that interfaces would have.
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