158 Operating System WAGO-I/O-SYSTEM 750758-874/000-110 WAGO-I/O-IPC-C6ManualVersion 2.3.013.7.5 Web Server (lighttp)Lighttp is a program under GPL and is especially characterized by its speed. Theconfiguration relies on the Apache web server and can therefore be simplyconfigured. PHP5 support is also available to the web server, which is alreadyused for the WBM web pages.The I/O-IPCs web server is activated when delivered. It provides a graphicinterface through Web-Based Management by which you can configure the I/O-IPC. For this, see section „Configuration via Web-Based Management (WBM)“.The already stored web pages can be found in the directory /var/www. In thedirectory /var/www/cgi-bin/ is a CGI parser that enables the creation of dynamicweb pages. Examples using the CGI parser can be found in the directory/var/www/wbm and implement WBM for the configuration of the I/O-IPC.13.7.6 NTP ClientAn NTP client functionality is provided for the I/O-IPC through the programntpclient. With NTP, the time can be requested from a remote NTP server throughport 123.If NTP servers are activated in the Internet, routing and firewalls must be suitablyconfigured. In NTP, the time is transmitted as a 64-bit value and has a resolutionof about 0.25 ns. The precision of the time transmission is given as +/-10 ms inthe Internet and up to +/-200 μs in local networks.The configuration and activation / deactivation of the NTP client is done throughWBM.
