"UForte OPC Historian" designed to archive data from OPC DA servers. It can be freely configured to collect data from many OPC servers simultaneously. Servers and items are specified in the configuration of "OPC Historian" by the user. "OPC Historian" is persistent to uncertainties in OPC servers. It doesn't matter if some server stops or fails - "OPC Historian" closes all connections to this server and establishes new ones (if it is possible or repeats attempts until failed connection will be restored). Data from OPC servers are stored in a DB in a serialized format. This allows processing many thousand OPC items at a time. Archive data can be retrieved from cache and from DB using GUI of "OPC Historian" and can be saved into xml file. XML is very popular format which is supported by many vendors, e.g. you can load this xml file into Microsoft Office Excel to analyze data, build plots etc.