en:netzer:websockets

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en:netzer:websockets [2013/02/22 21:53] – sveschen:netzer:websockets [2025/06/11 20:42] (current) – external edit 127.0.0.1
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-====== Why WebSockets? ======+====== WebSocket ====== 
 + 
 +WebSocket is a protocol for bidirectional communication between a web application and a server via a TCP connection.\\ 
 +Netzer uses WebSocket as a channel for the [[commandinterface|command interface]]. 
 + 
 + 
 +====== Why WebSocket? ======
  
 In normal HTTP a client (i.e. the browser) sends a request to a server. After some processing time the server responses to the client. This is one way, the server can not serve files or data by itself without been requested before. In normal HTTP a client (i.e. the browser) sends a request to a server. After some processing time the server responses to the client. This is one way, the server can not serve files or data by itself without been requested before.
 This is a disadvantage i.e. if data must be asynchronously refreshed. In such cases the client has to poll the server which leads to a lot of traffic. This is a disadvantage i.e. if data must be asynchronously refreshed. In such cases the client has to poll the server which leads to a lot of traffic.
  
-WebSockets are a possibilty for bidirectional communication between server and client. Client and server can send data on demand - Both are equal communication partners. While refreshing data it is enough to send data as soon they are available. It is not necessary anymore to poll the server.+WebSocket are a possibilty for bidirectional communication between server and client. Client and server can send data on demand - Both are equal communication partners. While refreshing data it is enough to send data as soon they are available. It is not necessary anymore to poll the server.
  
 <note important> <note important>
-Netzer supports Websockets since Version 1.5!+Netzer supports Websocket since Version 1.5!
 </note> </note>
 +
 +
 +====== Limitations ======
 +
 +Because an active WebSocket connection needs an active TCP connection to the web server of Netzer the further access of web pages is blocked.
 +Also only one simultaneous WebSocket connection is possible.
 +
 +
 +===== Supported commands =====
 +
 +All commands of the [[commandinterface|command interface]] are supported.
 +There are no WebSocket specific commands. 
  
 ====== WebSocket URI ====== ====== WebSocket URI ======
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 Showing the current value of the Netzer pin IO0. Showing the current value of the Netzer pin IO0.
 <WRAP center round download 60%> <WRAP center round download 60%>
-{{websocket.htm|}}+[[@/examples/websocket_en.html|websocket.htm]]
 </WRAP> </WRAP>