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[J Mack]

Hi,

I have several DCS3716 located around our factory. Some of these are used for a live view of mechanical processes.

I am connecting these cameras on a Debian host running VLC on an RTP protocol. The local switch is a HP J9562A.

There are frequent and recurring drop outs from the cameras that are causing freeze screens or black screens on the output client. VLC is set to reconnect a dropped connection and performs fine in test situations, but not in the real world. Having frequent complaints about having to restart VLC to resume the feed.

Here's a network monitor graph of what's happening

over 2 days


and you can see clearly over 2 hours, of an individual incident


As you can see the network isn't dropping completely (which would actually be preferable), but just enough to ruin the connection with the viewer.

I have 4 cameras all behaving the same as this

Any suggestions on the cause of this please?

[FurryNutz]

• Any 2.4Ghz or 5Ghz cordless house phones or WiFi APs near by that maybe causing interferences?
• Any other WiFi routers in the area or something else, that maybe causing interferences? Link> Use InSSIDer to find out. How many? Use v3, its free.
• What wireless modes are you using on the main host router?

Try changing channels on the main host router?

[J Mack]

It's cat5e wired to a HP J9562A switch.

[FurryNutz]

What happens if you bypass the switch and wire direct to the main host router as a test...
Need to rule out wiring and the switch.

[J Mack]

There is no router involved, it's purely on a local network. The switch is fine also, I can see that with my monitoring application. The wiring is fine too, it was end to end tested on installation. It stands to reason that it would be highly unlikely to be 4 sets of bad wiring that are causing the same issue, with the same frequency, at the same time. (which could also indicate a switch fault, but no.) The signal drop is occurring at different times on the different cameras but with the same interval. This also rules out the host NIC.

The graphs I posted are the signal from a single camera's tcp/ip connection with VLC.

There is some underlying issue/setting/configuration/something with the cameras or VLC I am not aware of.

[RYAT3]

This is a poe from the switch?  Can you tell if it is power related drop out in the cams vs network? Are there lights on the cam that turn off? (Thinking outside the box here)

[J Mack]

Yes it's POE from the switch.

I would think that if the if the power to the cams was dropping out sufficiently to interrupt the signal it would also crash the camera, and that all the cameras would be doing this at the same time. But it's not simultaneous. If I shut down a camera and then restart it the pattern starts again from that point in time. In testing now I have two cameras like this dropping simultaneously and another two at completely different times.

[J Mack]

Digging at it I noticed my VLC startup script wasn't implemented properly, this revision seems to work.

To start 3 cameras go to 3 different VLC instances on login, each instance to fullscreen on a specific monitor...  and restart on network loss.

Code: [Select]

#!/bin/bash
vlc rtsp://admin:@blrcam3:554/live1.sdp --loop -R -f --qt-fullscreen-screennumber=0 &
vlc rtsp://admin:@blrcam1:554/live1.sdp --loop -R -f --qt-fullscreen-screennumber=1 &
vlc rtsp://admin:@blrcam2:554/live1.sdp --loop -R -f --qt-fullscreen-screennumber=2 &
Hope this helps someone in the future.

[FurryNutz]

Glad you found the solution. Enjoy. 

[RYAT3]

I found some suggestions on the net about not enough poe on all ports in infrared is on. ..

Well who knows what the camera will do if power  drops slightly.