Overview of ChemWeb Server
The ChemWeb Server is used for central recording, monitoring and logging of the process data in potable and swimming pool water treatment plants. It is especially suitable for smaller installations without process display but which are to be installed with a data recording system with simple display. Another application example would be in unmanned plants such as potable water stations, in which recording of the measured data is to be accomplished by remote access.
The data exchange with the MG/L 5 and metering technology is accomplished via a serial digital interface. Data of process devices without serial digital interface can be recorded by the ChemWeb Server by means of the process data interface (PDI). By using an RS485 bus system, a variety of process parameters from the individual devices can be recorded, with little wiring. It is also possible to change certain process parameters with the digital communication. Parameters such as set point values, alarm contacts, etc. can be modified centrally via the ChemWeb Server. The RS485 bus system can be used for distances of up to 4,000 ft (1200 m).
To fetch the measured data from the connected devices, an HTTP server is integrated in the ChemWeb Server, the page frames of which can be called up via different interfaces depending on the version:
-local network (Intranet)
-analog, ISDN modem
-data exchange via CompactFlash card
-serial interface RS232
The ChemWeb Server behaves as a master at the RS485 bus and therefore cannot be used in connection with other data recording systems such as e.g. control stations, CMS, OPC servers, SECO S7, MF485 printer logging, or Profibus DP converters.
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