The TOP Server supports device and Network redundancy through it’s system tags which you can use to switch which device your connected to or even which Ethernet Network your connected through.  With critical data it’s important to have redundant systems, when that means having redundant data gathering too.  If you need OPC Server redundancy you can add the OPC Redundancy Master to make this easy. 

Features for OPC Server Redundancy

• Automatic switching to secondary server on failure of primary server
• Works with any OPC Data Access Application
• Supports multiple OPC Server pairs
• No programming or application changes required
• Hot, Warm, and Cold fail over modes
• Configurable Server polling intervals
• Trigger fail over and fallback
• Configure multiple monitor items
• Diagnostic and event logging
• E-mail notifications