UA Web sockets architecture | OPC UA Standard | Forum

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
UA Web sockets architecture
Avatar
Jacky Bek
Member
Members
Forum Posts: 14
Member Since:
12/13/2020
sp_UserOfflineSmall Offline
1
04/07/2021 - 17:26
sp_Permalink sp_Print sp_EditHistory

I like to confirm the architecture involving opcua and web sockets implementation:

At the edge side:
Opcua server#1-> web socket server#1 installed with libwebsockets library

At the cloud side:
Opcua server#2 -> web socket server #2 installed with libwebsockets library

web socket server#1 <-> web socket server#2 persistent connection over internet

please advise if my understanding above is correct.

Avatar
Randy Armstrong
Admin
Forum Posts: 628
Member Since:
05/30/2017
sp_UserOfflineSmall Offline
2
04/07/2021 - 18:22
sp_Permalink sp_Print

One of your servers needs to be acting like a client.

Servers dont talk to Servers.

Avatar
Jacky Bek
Member
Members
Forum Posts: 14
Member Since:
12/13/2020
sp_UserOfflineSmall Offline
3
04/07/2021 - 20:41
sp_Permalink sp_Print sp_EditHistory

Oh maybe I amend the architecture as follows:

———

At the edge side:

Opcua server#1 and web socket proxy#1 installed with libwebsockets library :: listener 

At the cloud side:
Opcua client#2 and web socket proxy #2 installed with libwebsockets library :: connecting to edge

once opcua client#2 completed the handshake with opcua server#1 via proxy#2 and proxy#1, a persistent connection will be established as follows:

Opcua server#1 <- web socket proxy#1 <- web socket proxy#2 <- opcua client#2

::persistent connection over internet A<-B ie B initiates connection request,

Avatar
Randy Armstrong
Admin
Forum Posts: 628
Member Since:
05/30/2017
sp_UserOfflineSmall Offline
4
04/08/2021 - 13:36
sp_Permalink sp_Print

That seems reasonable.

What software are you using to connect web socket proxy#1 and web socket proxy#2?

Avatar
Jacky Bek
Member
Members
Forum Posts: 14
Member Since:
12/13/2020
sp_UserOfflineSmall Offline
5
04/09/2021 - 00:10
sp_Permalink sp_Print

I just tried libwebsockets library to build a proxy server, and tested with a generic web socket client successfully.

My plan is as follows:

1. extend to opcua server by fronting it with a web socket proxy server

2. Use the same web socket client to access opcua server via the proxy server

once this is successful, I will extend to 2 instances of proxy server to simulate WAN connection.

 

i am not using any cots https server eg ibm, Apache for now

Forum Timezone: America/Phoenix
Most Users Ever Online: 202
Currently Online:
Guest(s) 9
Currently Browsing this Page:
1 Guest(s)
Top Posters:
Forum Stats:
Groups: 2
Forums: 9
Topics: 854
Posts: 2596