# DVT Cameras

S

#### Steve

I have a Legend Series500 DVT Camera that I am unable to communicate with. I am able to Force Diagnostics, but camera is unresponsive and at times cannot find it on the network. The cabling is good (have connected other DVT cameras up to it) and are able to ping the sensor. Any ideas (other then my current one of tossing it against a wall)

I

#### Ivan

Have you checked the IP address for the camera? You must set it up right so it will always sees it.

K

#### KGS

I have three cameras, had communication problems with all of them. With all of the cameras I have to go through a ritual.
1. Tried to get line with CAMERA X could not
2. Tried to ping it could not
3. Powered the camera down and back up
4. Got right online (surprise).
Sometimes it will just knock you off line when you're programming and it won't let you back on until you cycle power. But I've had the same
problems where I can force it into diagnostics but cannot get online. I have the right IP addresses and gateway and settings.
1. Tried to get online wouldn’t let me
2. Tried to ping it could not
3. yellow warning triangle on the plc for the DVT status
4. Went down to the camera and the status light is solid red
Results light would not come on when triggered
5. Powered down the camera and back up, status light comes up solid green after start up procedure
6. Result light works like it should
7. Went right online
Aggravating isn't it
Sorry I couldn't help but I would like to know of other problems with these cameras.

C

#### Curt Wuollet

Hmm...

I solved this problem with commodity board cameras, (570 lines resolution, $150.00)$40.00 BT848 based framegrabber cards and the free software that comes with Linux. Much cheaper, and it's no secret what's going on.

Regards

cww

C

#### Craig

Are you saying that you can get some DVT functions with OSS? Please let me know what software you are referring to. I've searched but haven't found anything yet (tons of bad links). I would like to try this.

M

#### Mark

You could get 'DVT functions' if you were to rewrite the DVT stuff. Why re-invent it? Use the DVT camera.

I would use the DVT camera. (Actually, I do use the DVT camera.) Use the published protocol information to query it on your OSS platform. Unfortunately, you'll still need MS Windoze to run DVT's FrameWorks for programming the camera.

Try looking at

"ftp://www2.dvtsensors.com/documentation/Manuals/CompleteCommandList13.pdf":ftp://www2.dvtsensors.com/documentation/Manuals/CompleteCommandList13.pdf

for the complete command list of commands.

You can test them by using telnet on _any_ PC connected to the camera.

Mark

C

#### Curt Wuollet

It depends somewhat on exactly what you have to do. What I have been doing is mostly grabbing a frame and doing measurements by pixel counting. I have done more sophisticated stuff as well but that was for a client and I can't really get into it. Anyway, here's what is easily available.

RedHat Linux (and most others I'm sure) has support called V4L for BT848 framegrabber cards out of the box. I have used Avervideo cards ($40.00) and Grand cards ($150.00). You can view video from a camera attached to the framegrabber at a reasonable frame rate on a commodity PC. The viewer I've used is called xawtv. This will be useful. There are others. There is a recorder called BTTV which will save frames as .jpg or some other format, Let's consider monochrome which makes things simpler.

I like PGM format as this is just raw pixels. For the simple applications I have been doing I simply grab a frame into an array declared like: char or int frame[640][480]. frame[0][0] is the upper left corner of the stored picture. The first line ends at frame[639]. You do this by simply stripping the header from the PGM format and assigning the rest of it to the array. In the 8bpp PGM format, there are 256 levels of gray. From here, you can do anything. There are many free image processing libraries available. Intel made a good set available and the PBM utilities are available on most distributions. Since this is OSS you can use them as is or simply copy the algorithms you need into your own program. So far, you've spent \$200.00 for a camera and written perhaps half a page of code. Everything else is courtesy of the community. If you understand what you need to do the stuff to do it is available.

If you want to go this route, I suggest google searches on V4L, BTTV, xawtv, etc. I've got a reliable, pared down single frame grabbing example program I can share to get you started. It will help to know C on Linux, but the education is free as well. Live video apps will, of course, require more complex software, but free examples are available for this as well. I do the processing, then send the data with either serial or ethernet comms to the machine that needs it. Mostly serial, as few automation machines allow you to find out how their ethernet works. When you're done, there is never any mystery about what's going on. You can simply
put in debug statements to tell you.

Regards
cww

R

#### Rokicki, Andrew

I am also interested OSS (Linux). Is there project for visual inspection ? I have been looking for something for a while.
I am tempted to start writing something, but instead of starting from NULL it would be much more productive to join an existing project.
Thanks.

C

#### Curt Wuollet

There isn't a specific project for machine vision that I know about. This would be a wonderful project to start. Perhaps, when (if) I find a job, I'll write a GPL version of what I was doing. It's simple Bonehead C (tm.) and single purpose, but might be good enough as a stone for the stone soup. I might as well be on DVT's excrement roster too.

Regards

cww
--
Free Tools!
Machine Automation Tools (LinuxPLC) Free, Truly Open & Publicly Owned
Industrial Automation Software For Linux. mat.sourceforge.net.
Day Job: None, are you interested?
Consultancy: Wide Open Technologies: Moving Business & Automation to Linux.