Does the TranslateBrowsePath operate only at first level of the reference? It is possible to achieve // like in xpath?|OPC UA Implementation: Stacks, Tools, and Samples|Forum|OPC Foundation

Avatar
Search
Forum Scope


Match



Forum Options



Minimum search word length is 3 characters - maximum search word length is 84 characters
Lost password?
sp_Feed sp_PrintTopic sp_TopicIcon
Does the TranslateBrowsePath operate only at first level of the reference? It is possible to achieve // like in xpath?
Avatar
Rudolf Pribis
Member
Members
Forum Posts: 4
Member Since:
03/04/2019
sp_UserOfflineSmall Offline
1
03/27/2023 - 00:22
sp_Permalink sp_Print

Dear all,

maybe it is a silly question, but is the TranslateBrowsePath capable of doing of doing something like the XML xpath (e.g. bookstore//book Selects all book elements that are descendant of the bookstore element, no matter where they are under the bookstore element)?

if not, what is the proposed way of doing something like that?

Avatar
Randy Armstrong
Admin
Forum Posts: 1579
Member Since:
05/30/2017
sp_UserOfflineSmall Offline
2
03/27/2023 - 06:55
sp_Permalink sp_Print

No. The main reason is an OPC UA Server is not an XML document or an OO database that can be easily searched with complex queries. In many cases, following references requires multiple subsystems to be interrogated to find out what information is currently present.  With some servers, loading all possible nodes to resolve those types of queries is not technically viable.

In the future, some OPC UA servers will support a service based on GQL: https://www.gqlstandards.org/w…..l-standard

Avatar
Rudolf Pribis
Member
Members
Forum Posts: 4
Member Since:
03/04/2019
sp_UserOfflineSmall Offline
3
03/27/2023 - 11:56
sp_Permalink sp_Print

Randy Armstrong said
No. The main reason is an OPC UA Server is not an XML document or an OO database that can be easily searched with complex queries. In many cases, following references requires multiple subsystems to be interrogated to find out what information is currently present.  With some servers, loading all possible nodes to resolve those types of queries is not technically viable.

In the future, some OPC UA servers will support a service based on GQL: https://www.gqlstandards.org/w…..l-standard

  

Thanks for the prompt clarification.

Forum Timezone: America/Phoenix
Most Users Ever Online: 510
Currently Online:
Guest(s) 37
Currently Browsing this Page:
1 Guest(s)
Top Posters:
Forum Stats:
Groups: 2
Forums: 10
Topics: 1446
Posts: 4890