I have 800xA V5.1. Trends take time to display in trend display.sometimes don't trend at all.
Could be any among many reasons.
1. Check if RTA or AC450 is highly loaded (<50% resp <80% is recommended max)
2. Check if RTA or AC450 emit any system messages when connecting them with RTA Board Config / OnLine Builder (remember to turn ON message display "To Screen" in settings).
3. TTD or OPC logging? TTD require 100% match between AC450 and 800xA. Use TTD Synchronization to bring configuration to 100% sync.
4. If trend status blink "yellow" for long time before data arrive/going green one could suspect the 800xA System Network Filter to be incorrect set in the Configuration Wizard, or not set at all sending client's trend request on a "detour" before reaching the correct server.
5. Basic History service overloaded or improperly configured. Please check CPU load and memory size for AdvHtHistorySrv.exe process on connectivity servers. Also the service provider statistics in the Service Structure may contain clues (e.g. number of concurrent trend requests in queue, etc.).
6. Poor bandwidth in conjunction with large time scopes and Momentary Trend Treatment is also known to cause slow action in trend displays. Ensure client/server network speed is good and use TimeAverage Trend Treatment in trend template for most kinds of trend requests (at least when time scope if > 1 day). Use ExtMomentary for short time scopes only. Never use Momentary.
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