Server status

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Displays information about the server's network status, and how many clients are connected. Here's an example:




Version information. This display is from WhiskerServer v2.0, multimedia edition.


Network status. Since the server is accepting connections from clients, the network status shows as 'running'. The server's name and IP address is displayed. (In addition to this IP address, the address can be used to mean 'this computer'.) Every TCP/IP based program makes a connection using a port number (for example, the HTTP protocol that drives the Web usually uses port 80) and the TCP port that Whisker uses by default to establish connection is 3233.


Connected clients. This example shows that two clients are currently connected, and there is an arbitrary limit of 64 clients. (If this limit causes problems, e-mail


Performance information. The bottom section of this display shows performance information. Whisker operates by asking the digital I/O boards very frequently whether anything has changed since it last asked, a technique known as polling. In this example, the longest time between two consecutive polls since the server was restarted (or the timing statistics were reset) is 2 ms; the display you are looking at will be updated approximately once every 1000 ms; the worst inter-poll interval since the display was last updated was 2 ms, and since the last display update (1000 ms ago) there have been 1008 pools, all of which have occurred with 10 ms between them (in fact, in this case, we know from the previous numbers that Whisker was performing rather better than this and no inter-poll time was longer than 2 ms). The meaning of this information is discussed in more detail later (Whisker — Performance considerations).


Technical note: why use polling?


Because the Amplicon boards cannot generate interrupts when an arbitrary input line changes state.