Software development of dual axis galvo system scanner for laser marking

[NIquist]

It appears there are LabVIEW drivers available from Coherent but I don't know what might be appropriate to your particular model.  Check out the link below and see if any of the drivers apply to your laser:

https://www.coherent.com/Service/index.cfm?fuseaction=forms.page&pageID=96

[sabrinah]

Unfortunately  no drivers are available for this model. According to the manual we can give instructions to the laser using a serial software command. Two types of instructions are used:

- Commands which set the values of laser operating parameters

- Queries which request the laser to return a value of an operating parameter

Any instruction to the laser consists of a command or query written as a string ASCII characters and terminated by a carriage return and line feed.

[NIquist]

Too bad about no drivers but I think that model is pretty new.  What you need to find out is if there is any way to actually fire the laser through the comm interfaces.  If not, there is no choice but to have some way to generate a digital signal from your controller PC.  Again, a multifunction DAQ card is ideal since it has both analog and digital I/O and you can offload the synchronous job (between mirror motion control ramp and digital 'fire' signals) to the DAQ card and let it do the timing.  Doing the timing on the PC means you'll have to deal with the inherent, non-deterministic delays caused by the PC's operating system.  That will induce sloppy jitter into the synchronization.  Have you talked with your NI rep again?

[sabrinah]

Hello,

I sent an email to my NI rep and I'm currently waiting the answer. I can send order to the laser via serial commands. 

[sabrinah]

Another question related to NI Vision Software. I'm currently using LabVIEW thanks to the server name of the University. I installed VAS_2015_08_F1 but all examples and some functions like IMAQ calibration miss. Is it because it's trial version?

Thanks! 

[NIquist]

NI-Vision comes in several packages so you can tailor your purchase (or free installs) to your needs.  There is also the Vision Development Module and IMAQ/IMAQdx/IMAQ for USB options.  See links below...

http://www.ni.com/vision/software/

http://digital.ni.com/public.nsf/allkb/A451D3CCBB740716862578FC004DB392

http://www.ni.com/example/30030/en/

[sabrinah]

Thanks,

I started to create a program which from an imported image gives the value of pixels and their coordinates for then control the mirrors of the scanner. For the first part (pixel value) it's ok but I'm confused about the function calibration. I'd would like to obtain the 'real word' coordinates and for that I calibrated my image. It is specified that Real word coordiantes returns a cluster of real word point coordinates that corresponds to the points specified by Points coordinates . I searched but I didn't find the way to find this info. Can you help me?

Thank you very much!

[NIquist]

My company has just bought a big NI Enterprise package but our new licensing isn't in place yet so I don't have any Vision tools.  I can't even open your code right now since we are still using LV2014.  You can back save your VI to 2014 and repost so I can take a look.  My only experience with calibrating to real-world measurements was done with a small image that was viewed through optics that made it easy.  We just had a small cross marked onto our target that we knew the exact dimensions of and used that to convert pixels to millimeters.  For your application it may be a bit more complicated.  

Take a look at this for some related info:  http://zone.ni.com/reference/en-XX/help/372916J-01/nivisionconcepts/spatial_calibration/

[sabrinah]

Hello,

in fact I don't manage to display the matrix of real world coordinates, I just obtain (I suppose) the display of the conversion of the first element of the pixels matrix (0,0)...I guess I need to add an input in the funtion 'Real world coordinates' like the X and Y position and a calibration axis but I don't know how.

Thanks!

[NIquist]

It looks like you're on the right track but it's been a while since I did any Vision apps.  I generally started out with the Vision Builder (http://www.ni.com/vision/software/vbai/) and just convert into LaVIEW code after I set up most of the application with the Builder.  It's almost cheating.    

We now have our NI updates available so I can install the IMAQ  tools you are using and some Vision tools you could be using that might make life easier.  It may take some time to get to this though as I'm taking tomorrow off for the LabVIEW Developer's Day and will have to do some catch up work to make up for the day off.  

In the meantime there is also a NI forum dedicated to Machine Vision:  http://forums.ni.com/t5/Machine-Vision/bd-p/200

I suggest you post there as well and provide a link to this topic so the posters on the vision forum will know where we're at with your application.  Hopefully there is someone over there who has done this more recently than I and can chime in with some pertinent advice.