Data Monitor

"Data Monitor" is used to view Telemetry and Attributes (client/shared/server) of a device in real-time in the management console, suitable for field troubleshooting and integration verification: You can quickly answer "Is device reporting", "Is value changing", "When was last update".

Applicable Scenarios

• Field Troubleshooting: Device data intermittent, high latency, suspected data loss, quickly confirm if gateway side has collected latest value
• Integration Verification: Driver/Point mapping just changed, confirm if key is correct, if value changes as expected
• Decouple from Northward Link: Confirm "Collection is normal" first, then check "Cloud upload is normal", avoid guessing both ends

Telemetry vs Attributes

• Telemetry: Usually represents high-frequency collected/reported time-series data (Point value, sensor data, etc.)
• Attributes: Usually represents relatively static or low-frequency changing attributes
  • client: Attributes reported by device/client side
  • shared: Attributes issued/shared by platform side
  • server: Attributes maintained by server side

In monitor table, sourceType identifies whether current row comes from telemetry or attributes.

User Guide

1. Select Channel
   • Used to load device list under this channel, avoid blind selection in large number of devices
2. Select Device
   • Establish WebSocket connection and subscribe to data stream of this device after selection
3. Search by Key
   • Input keyword in "Search Box", filter by key (Case insensitive)
4. View Table Fields
   • Device Name: Device Name
   • Key: Point key / Attribute key
   • Value: Current value (May be object/array etc. complex JSON)
   • Source Type: telemetry or attributes
   • Last Update: Last update time of this device (Server timestamp)

Refresh Semantics and Performance Boundary

To ensure stable usage in "High Throughput + High Frequency Point" scenarios, monitor link implements two layers of "Rate Limit/Merge":

• Server-side Merge (200ms Window): Server merges point updates of same device within short window before pushing, avoiding UI being flooded by one frame per point
• Frontend Throttle (200ms Min Refresh Interval): Frontend throttles UI update, avoiding frequent table redraw

In addition, table rendering implements pagination optimization:

• Render Current Page Values Only: Only "Inject realtime value" for current page rows during pagination, controlling refresh cost to (O(pageSize)), avoiding browser lag when point quantity is large

Known Limitations and Notes

• Need "Device Snapshot" First: Monitor depends on latest snapshot of device on gateway side; if device never reported data, may not display any row
  • Suggest confirming first: Is device connected, collection started, data reported to gateway
• Ambiguity of Same Name Attribute Key: Same key may exist in client/shared/server simultaneously, UI internally distinguishes rows by scope (Avoid conflict)

FAQ

1) What if Connection Status shows "Disconnected/Connecting/Reconnecting"?

• Check API Gateway Address and Network First: Can browser access gateway management port
• Check Auth Status: Is login expired (WS may be rejected after expiration)
• Check Browser Console: If WebSocket connection rejected/401/403, usually permission or auth issue

2) Selected Device but Table Shows No Data?

• Device Has Not Produced Snapshot: Monitor cannot display key list when device never successfully collected/reported data
• Driver/Channel Not Started or Connection Failed: Check channel connection status and collection status first
• Confirm Point Model: No point configured/No uplink output, telemetry keys will not appear either

3) Value Shows undefined or Empty?

• The key may exist in "Metadata List", but current snapshot does not contain value yet (e.g., newly added key, not reported yet)
• Suggest waiting for next device report or resubscribe (Switch device and switch back)

Troubleshooting Suggestions

• Check Metrics and Backpressure First: If queue backpressure or drops are obvious, realtime monitor may also have delay
• Then Divide Direction: Is southward collection normal? Is northward upload normal?