USB 2820 devices

[rich.compton]

I am currently trying to debug why a camera is not working with my twain solution. It uses the twain driver in the USB2800 folder (emTwain.ds). As far as I can tell from some googling that several different cameras are USB2800 and 2820? What are these?

The problem I am running into is when I enable the source and choose to display the source dialog, I see the camera stream but nothing else. No dialog. When I use a licensed twain solution (dynamsoft) I see a dialog (generic lookg 2800 USB device capture dialog).

Any ideas?? Does anyone have any knowledge on these devices??

Thanks in advance.

[spike]

I have no idea what that USB2800 is – your camera vendor’s TWAIN driver. They would be the ones to ask.
You can try making a copy with a .dll extension, then right-click on it and view Properties – Details. Sometimes that will have a description, copyright, etc.

However, the difference in behavior of the scanner between your app and Dynamsoft? That could be two things:

1. You are trying to enable the camera in NoUI mode and the driver doesn’t work right. Not uncommon, especially for cameras.
Try with a 3rd party app that can operate in No-UI or With-UI mode – the sample app from the TWAIN toolkit, or e.g. Twirl: http://www.eztwain.com/twirl.htm

2. Your app isn’t handling the message-pump correctly, so messages aren’t delivered to the TWAIN driver that it needs to create & operate its dialog. Are you using a 3rd party library to do TWAIN or did you roll your own code?

[rich.compton]

The USB2800/emTwain.ds is definitely what the manufacturer wants to use for this camera. The reason I was wondering if it is a generic USB cam twain driver is because I have seen it used with a few cameras now. I will try the manufacturer as you say and email them a few questions.

I have written my own code that is based on the sample code that comes with the SDK. As mentioned in my other thread that you answered, it seems to work for most other devices. The wia and USB2800 that keeps coming up are the only ones that don’t fully work. My message pumping is where I thought the problem could be as well but it seems to work well with the sources dialogs for the other 11 devices I have tried. My guess is still something is wrong in that section of my code.

I will try the twirl link you sent me and let you know

Thanks for all your help 🙂

[rich.compton]

Just downloaded and tried Twirl. The USB2800 does the same thing. It works even less. I can’t see the video stream at all. No dialog at all (and yes I enable device u/i ).

On a side note, twirl seems to work less. It crashes trying to using one of the network scanners that I use, it fails to load another source and has a fatal crash on the laptop camera.

Have you used twirl a lot? Is the pro version worth it?

[spike]

Yes, I’ve used it a lot. There is no Pro version – or rather, that is the Pro version, there’s no limited version.
Usually when it crashes it means there’s a bug in the driver, but that doesn’t sound like an adequate explanation here!

Let’s see if there’s a newer version around that hasn’t made it to the website. Hold a mo…
There is a newer version we should try, but it will take me a while to get it up on our website.
Will post back tomorrow before noon (US Eastern Time)

[rich.compton]

Great sounds good thanks again.

I am looking at the library sdk now. Trying the trial to see how it works.

[spike]

Sorry for the delay, I’ve updated the Twirl version on the eztwain website, you can download it from the Twirl home page at
http://eztwain.com/twirl.htm

Let me know how that works, if it misbehaves we’ll see if we can track down the problem.

[Author]

Posts