JSON/JavsScript WebSite Feedback and Questions |OPC UA Implementation: Stacks, Tools, and Samples|Forum|OPC Foundation

Hello

I just tried the demosite prototyping.opcfoundation.org, and when using the Subscribe demo, its unable to connect to the OPC-UA Server at address prototyping.opcfoundation.org:62542. I remember the trainer from the demo said he had to open the port temporarly.

So am I right with the assumption that this sample will not work anymore at all or is it just a network / server issue and the server should be reachable again?

I want to build my own node.js / React / Typescript sample here in my office and need a server to get the data from.

Greetings and thanks for the nice example.

Alex

Since the presentation the websocket example uses the non-reversible form (the example before used the reversible form).

Could you change it back to the reversible form?

NotificationData provides an array of ExtensionObjects and in the reversible form the type id of this ExtensionObject has to be present

This is not the case in the example:

{
    "TypeId": {
        "Id": 827
    },
    "Body": {
        "ResponseHeader": {
            "Timestamp": "2020-04-14T06:15:08.4207221Z",
            "RequestHandle": 6,
            "StringTable": []
        },
        "SubscriptionId": 15,
        "AvailableSequenceNumbers": [
            2
        ],
        "MoreNotifications": false,
        "NotificationMessage": {
            "SequenceNumber": 2,
            "PublishTime": "2020-04-14T06:15:08.4207221Z",
            "NotificationData": [
                {
                   "!!!!!!!!!!! TypeId IS MISSING !!!!!!!!!!!!!!!!!"
                    "Body": {
                        "MonitoredItems": [
                            {
                                "ClientHandle": 1,
                                "Value": {
                                    "Value": {
                                        "Type": 11,
                                        "Body": 1.789481742797868e+35
                                    },
                                    "SourceTimestamp": "2020-04-14T06:15:07.5858651Z"
                                }
                            }
                        ],
                        "DiagnosticInfos": []
                    }
                }
            ]
        },
        "Results": [
            0
        ],
        "DiagnosticInfos": []
    }
}

I have a architectural question to the solution:

does the browser communicates DIRECTLY to the opc ua server or 

is the communication always between browser <-> webserver <-> opc ua server

I dont get it, hope you can give me some insights

Hi. This seems to be a old post, but since it is a sticky I will try to post here instead of making a new post. 

1) The server/example seems to be down? Is it running on another URL?

2) Is the source code for the example available somewhere?

We are building a automation system using PLCs (Siemens and/or Codesys) but for the HMI we need to use standard html/js/web browser functionality. We are a bit stuck on the best architecture on this system. The PLS and HMI are on the same physical network, so they should be able to communicate with each other without to many security restrictions. We would like to reduce the complexity and number of hardware/servers to facilitate communication between the PLS and HMI, and thus would like to use standard REST API or websockets to communicate "directly" with the PLS without needing a web server/proxy/etc in the middle. Is this possible? 

Any one know if siemens and codesys supports JSON serialization and websocket communication? 

What are our options? We have made a working prototype using a "OPC-UA client to websocket server" using node.js in the middle but as mentioned previously it adds (unnecessary?) overhead and complexity.

Anyone knows if there is any opc-ua clients that works in the browser?