Reading your NVR log: what a lift camera's offline times tell you
The pattern of when the camera drops is the cheapest diagnostic you have. Export the log, mark the times, and read the pattern.
Before you open the lift well, open the NVR. Most recorders keep an event or system log that shows when each camera went offline and came back. Those timestamps carry more information than most people expect, because each cause of a lift camera fault has a different pattern in time.
Step 1: export a week
Export the event or system log for the lift camera for at least seven days (menus differ by brand; look under System, Events or Logs). You want the time of each disconnect, and the time it reconnected.
Step 2: mark the times against the day
Write the offline times against a simple timeline of the day: morning rush, midday, evening rush, night. You are not looking for exact seconds. You are looking for the shape.
Step 3: match the shape
| Pattern in the log | Likely cause | What to do | |
|---|---|---|---|
| Clusters in the morning and evening when the lift is busiest | Cable or connector in the moving section: more trips, more flexing, more drop-outs | Check for a cracking conductor and loose plugs; see [[/guides/lift-camera-video-flickers-or-drops-when-the-lift-moves | video flickers or drops when the lift moves]] |
| Starts at dusk and continues through the night, whatever the traffic | Power: infra-red LEDs or a heater raise the camera's current draw and the voltage dips | Check the run length and the switch budget; see [[/guides/ip-camera-in-lift-keeps-going-offline | IP camera keeps going offline]] |
| At regular intervals, such as every hour on the hour | Not the cable: a scheduled task, network lease or firmware setting | Check the NVR and switch settings | |
| Long outages with the lift parked | Fixed section, switch port or building power | Test the fixed run and the port; see the [[/diagnose | diagnosis tool]] |
An example, to show the idea
This table is illustrative, not data from a real building.
| Time offline | Duration | Lift in use? |
|---|---|---|
| 08:42 | 6 s | Yes, morning rush |
| 08:47 | 4 s | Yes |
| 09:05 | 9 s | Yes |
| 13:30 | None all afternoon | Quiet |
| 18:12 | 5 s | Yes, evening rush |
Drops only in the busy periods, each a few seconds long, with a quiet afternoon between them: the moving cable is the first suspect.
Then test
The log tells you where to look; it does not replace the test. Confirm the suspect with the check in the matching guide before you replace anything.
