What is the "WebServer2" on Saia PCD® COSinus systems?

FAQ #101191

 

History
The first implementation of a Web Server on PCD systems has been realized around the year 2000. With growing experience additional features and higher performance have been requested. In order to fullfil this requirement, the WebServer has been re-implemented (with the result of the WebServer2).

What is new in the WebServer2?
In general the WebServer2 is functionally compatible to the previous implementation. In addition the following new features are supported:

• HTTP 1.1 support
• HTTP caching is supported. As result the in FAQ 100708 is no longer to be applied; It is recommended to enable the caching for the JVM (option "keep temprary files on PC") when working with the WebServer2.
  
  Remark: If the caching is not enabled, you will not profit from the supported caching; it will then work as it has before with the previous WebServer. 
• Better performance
• Parallel acces to files is properly supported (acces is no longer interrupted if another client loads the IMaster applet)
• Multiple Web clients can access the Web Server on the same physical interface with (Ether-S-Bus or Profi-S-Bus)
• Easier understandable error messages
• When texts are entered, the length of the text is specified (and no longer filled up with space characters)
• The WebServer2 does provide more information on the default page and has a nicer look. By viewing this page it is easy figuring out whether the WebServer2 is running on a PCD
  

  View of previous WebServer	View of WebServer2

Firmware (FW) supporting the WebServer2
The table below indicates the first firmware versions supporting the WebServer2. Systems not listed in this table do not feature the WebServer2.

PCD system	pilot FW version	production FW version
PCD2.M480	1.09.38*)	-
PCD2.M5xx0	1.09.38*)	1.10.16
PCD3	1.09.38*)	1.10.16

^*) Please note that in the first pilot firmware not all features have been supported.

Remark
The only incompatibe difference between the previous WebServer and the WebServer2 concerns users that use the "HTML forms":

• The previous Web Server used:
  %%TAG%
• The WebServer2 expects (the "value" is no longer automatically added by the Web Server):
  value=%%TAG%

An example for the HTML forms on the WebServer2 can be found in the attached document.