black stripes - bandwith problem - Vision Builder AI

[declercq_tom@waak.be]

Hello,

I have a problem with an application in wich I run 4 Vision Builder programs on 1 computer. All seems to go well untill after a while (sometimes a couple of minutes, sometimes half an hour) I get black horizontal stripes over my images.

I have been searching this forum and found several posts about this problem. However, I tried the different solutions that were suggested and this doesn't seem to make a difference.

Information:

* 4 camera's (Allied Manta G201C)

* camera's are triggered (rising edge) seperately but almost simultaneously.

* PC: quadcore, 64bit-system, Windows 7 64bit

* Run-time license Vision Builder 2012.

* Programmed with Vision Builder AI 2012.

* Switch: 1000Mb

* Interface programmed in C# (receives images from the 4 programs and displays relevant info on screen).

Tried methods:

* Set packet size to 1500 (Even tried lower packet size without improvement).

* Set desired Peak Bandwidth to 250 without improvement (was originally set to 1000 - we set it to 250 because there are 4 camera's - Even setting it to 150 doesnt seem to improve the situation.)

* cursed alot - but that didnt seem to help either.

* Could we be using a switch that doesnt fit our purpose?

* Our switch is placed with several engines around it (closest about a meter away) and just behind an electricity cabin in wich there are several transfos. Can this affect our data?

* Other suggestions?

* Please let me know if you need extra info about this problem.

We are expecting our clients to visit us next week to see if we will be able to start production so we are currently under enormous time-pressure (and stress). So any help would be greatly appreciated.

With kind regards,
Tom

[BlueCheese]

Hi,

Check your user manual (or fiddle with the attribute tree) about how the throttling works on that camera. I seem to recall that by default on the AVT, throttling via the SCPDx register (what Desired Peak Bandwidth is adjusting) is ignored and the camera uses its own vendor-specific throttling control. You may have to either use their throttling control or tell the camera to honor the SCPDx mechanism.

Eric

[declercq_tom@waak.be]

Thanks Eric,

You might just be on to something. I've been checking out all the camera-info I could find and am going to check all my cam settings later today.

I'll keep you up to date.

Tom

[declercq_tom@waak.be]

Update:

We've:

* set the StreamBytePerSecond (in NI MAX) to 20000000 (was set to 115000000) / we divided by 4 because there are 4 cameras and then lowered sme more just to be sure.

* Made some changes to our network settings:

-----enabled Jumbo Packet / 9K

-----set Receive Buffers to 2048 (was 256)

-----set Interrupt Moderation Rate to Extreme

A first test for about an hour showed no more black stripes. We will test this for a longer period and if we no longer encounter this problem I will change the status of this thread to solved so that others can wont have the same problems.

Thanks a lot!

Tom

[declercq_tom@waak.be]

Update 2:

Unfortunately our problem isn't solved. Longer tests still show the black stripes.

In NI MAX we"ve set the parameters as you can see in attachment. I'm running out of ideas for the moment: Any other suggestions?

I also just enabled Advanced Inter Frame Spacing (Performance Options - Properties) of our switch. Hopefully this helps to avoid the data collision. If so I wil post this.

Thanks,

Tom

[declercq_tom@waak.be]

Update 3:

We seem to have found the solution:

We've disabled jumbo packets on our network card and left all the other settings as mentioned in earlier posts and we no longer have the black stripes. (For the moment we've been testing this over a period of almost 3 hours.)

Good to see the problem solved, but kinda frustrating that we dont know why.

Wtih jumbo frames enabled and packet size only 1500 we had the stripes, with jumbo frames disabled and packet size only 1500 we don't have black stripes 😕

Fot the moment I wil set this question as solved, but if anyone can explain this to me please do.

Thanks for the support everybody,

Tom

[ThiCop]

Hello Tom,

Can you provide me with some information about your NIC/network card?

I have seen some NIC's with some special issues (purely related to the packet size that was chosen).

Also important:

Which driver are you using for your Network card?

[declercq_tom@waak.be]

Hi Thierry,

I wil post the info you asked later. For the moment I am away from the system, but I'l be back there in about an hour.

Meanwhile, Update 4:

This is getting quite frustrating. After our 6-hour (!) test yesterday we did some more tests today. after a couple of minutes the black stripes were back.

Only difference between the test we did yesterday and the one we did today is that yesterday the cameras were taking pictures of empty carriers and every image was ok. Today we took images of carriers with pieces on them (some ok, some not ok).

For the moment I am thinking that there might be some interference when pieces are not ok. When a piece is not ok some lights go on and the piece gets diverted. Since our switch is placed very close to the electricity cabin this might cause interference.

Kind regards,

Tom

PS: I will certainly mark the question as solved if the problem ceases to exist. Kudos already given

[ThiCop]

Hmm, that indeed seems strange.

Don't mind my footer!

It's after all my posts and alot of people think that I am explicitely targetting them, which is of course not the case 🙂

The marking as resolved I just put there to make sure that people experiencing similar issues can later on easily find the solution.

[declercq_tom@waak.be]

Thierry,

Please find the info you asked in attachment.

kind regards,

Tom