Problem

Metasys UI suddenly shows all readings as "????" across all graphics. System was working yesterday. Operators can't read setpoints or status.

Root Cause

Network Engine (NAE/SNE) is offline or experiencing network communication loss. All downstream controllers unable to report values to Server.

Solution

1. Check Network Engine Status:

   • In Metasys Server, navigate to the Network tab
   • Look for the Network Automation Engine (NAE) or Site Network Controller (SNC)
   • If you see a red "X" next to it, the engine is offline

2. If Engine is Offline:

   • Check 24VAC power to the engine (verify with multimeter if possible)
   • Listen for the power supply—should have a slight hum
   • If no power, check circuit breaker and wiring connections

3. Verify Network Communication:

   • Check Ethernet connection to the engine (look for link light on port)
   • Try power-cycling the engine (unplug 10 seconds, plug back in)
   • Wait 2–3 minutes for full startup and discovery

4. Use FQR Hyperlinks to Isolate Problem:

   • Click on any "????" value in the graphics
   • In the pop-up, a fully qualified reference (FQR) will appear as a hyperlink
   • Click the FQR to navigate to the Network tab and see which controller owns that point
   • If the controller shows red "X", it's offline or unreachable

5. If Specific Controllers are Offline:

   • Check controller power and network wiring
   • Verify Ethernet switch port for that controller (check for link light)
   • Try replacing the network cable (bad cable is surprisingly common)

6. If Engine Restarted Recently:

   • Engine may be re-discovering controllers—wait 5–10 minutes for full sync
   • Check Event Log in Metasys UI for "discovery" events