Hi we are developing , a new WEB HMI for our SCADA system, so we need to update pages quickly and dynamically.
Is there a reason why
If Application.IsWebSocket = False Then
AlertBox.Show(“No web Socket”)
End If
return always “No web Socket” (false) ?
The call is in a Sub invoked after a click on Datagridview.
Websocket seems to be enabled in IIS 10 and when i run app under VS, call IsWebSocket return always true. I know in IIsexpress websocket is enabled by default.
Moreover performance are not as i expect , Application.update seems to be ignored.
I have tried with Chrome and Edge and i am using Wisej 2.2.47. At this moment i can’t update version, because my license is expired.
Any suggestion to solve the problem ?
What can i check ?
I have tried also to force enable in Default.json with no result.
Thank you in advance
Nello Pernice
Hi Nello, the issue is not in the browser, it’s the server that is refusing the connection. In the chrome console click on the second red line to open it and see if it shows the error code.
Try this: http://demo.wisej.com/codeproject
Open chrome F12 and look at the network tab. See screenshot attached. That’s what you need to see. If it doesn’t work it’s your server or something in between refusing the websocket connection. Could also be an antivirus.
Hi Luca,
Thanks for your help.
I’m sorry to bore you with my problem: the websocket is enabled, but in the Chrome console, in the WS tab, I see the request but I don’t see the Reponse. Also by expanding the error line there is no further information. the firewall is disabled and there are no proxies (the server is on the local machine). Even debugging on Chrome, the data field of the error parameter ( e.data) is “Undefined”. What else can I check? I attach screenshots of the Chrome console and of the IIS configuration.
For our critical application, a quick and specific update of the page is mandatory, so we need to use websocket .
Thanks in advance.
WebSocket is a native browser class. See the second red line (WebSocket Error) and expand it to see if there is an error code. Look also at the network tab, you will see an entry of type “WebSocket”, look at the headers and response, it may tell you more.
WebSocket works by sending an http upgrade request, the web server either accepts it and upgrades the connection or rejects it. Looks to me that it’s either not enabled or there is a proxy in between that is blocking the request.
Thank you for your answer.
I enabled Websocket in IIS10 but error is always there.
I have attached a screenshot of chrome console. If you have any suggestion about how to debug the problem i will appreciate very much.
The problem persists with all browsers.
Tks.
Nello pernice
Hi Nello,
By default IIS10 disables WebSocket, make sure that you have in enabled features.
If it’s enabled and still doesn’t work, check the console with F12 for a websocket connection error as it is usually caused by a proxy (load balancer or hosting service) not allowing WebSocket connections.
HTH,
Alaa
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