Downloading motion profile to the Motion Card

[K_seeker]

We are using a 2 Axis parker motion controller for a Vision+Motion Combo project. Every cycle the the vision system captures a new pictures of the part under processing. Based on image analysis results the Labview program generates a set of lines arcs and circles for the laser cutting tool to perform the cutting operation. The parker controller  (6K2)works great for motion but it takes a long time to download the motion profile. Also the 6K2 needs to compile the motion profile before it can execute the path. On average it takes about 15 to 25 seconds for the download and path compilation to work. In short the 6K controller are not ideal for an application where the path will change frequently.

The customer would of course like to eliminate this time. I believe NI Motion controller card would work perfectly for this application. I would like to get some information before I commit to this project

1) Once the path is generated I believe it can be downloaded to the motion controller card and the processor on it will perform all the task without any assistance from the Host CPU. Which 2 Axis motion controllers have these features?

2) How long does it take for the generated path profiles to be written to the Motion controller? On an average path definitions could have upto 30 circles, 60 arcs and 60 lines.

3) Is there any limitation on execution of the downloaded program?

Thank you.

[Jochen]

You are right. As the NI motion controllers are PCI based devices you should expect a great performance improvment with these devices.

Here are the answers to your questions:
1.) The feature you are looking for is called "contouring" and it's available on these 2-axis controllers: PCI-7342, PCI-7352. Contouring allows you to download any type of motion profile to the motion control board and you are not limited to lines, arcs and circles.

2.) Downloading contouring data to the motion board takes only several milliseconds. You even can download the contouring data sequentially in little junks while the move is already running in order to either allow the generation of really huge mtoion profiles or to decrease the download time even further.

3.) Besides contouring the 734x and 735x also provide onboard programming. Onboard programs can be used to run additional tasks independently from the PC's CPU (e. g. to monitor the torque of a motor and stop the move if a user defined limit is exceeded).
Given the information that you have provided I don't see the need for onboard programming in your application.

I hope that helps,

Jochen Klier
National Instruments Germany

[K_seeker]

Jochen,

Thanks for the response. So now I am wondering what is the main difference between a 2 axis motion controller cards of 7340 and 7350 series. I can see two differences

1) 7350 can do breakpoint IO 7340 can not

2) 7350 has Analog IO 7340 does not.

Is there any other difference as far as 2D contouring performance is concerned? I do not need the above two features any way. So I beleive I can use NI PCI 7342 just fine?

Thanks

[Jochen]

The 735x series provides buffered/timed breakpoint and high-speed-capturing (HSC) features while the 734x series requires a software reenable for those operations which results in much lower breakpoint and HSC rates for the 734x.
The 735x provides more analog and digital inputs and a faster PID loop (62,5 µs for 2 axes compared to 62,5 µs for 1 axis with a 734x).

As far as the 2D contouring performance is concerned there is no difference between those two series so you will probably be able to use the PCI-7342.

Jochen Klier
National Instruments Germany

[hach77]

Hi K seeker,

I want to know if you still working on labview  and 6k2.
I am known in Labview. I did a program on MOTION PLANNER to control the movement of 2 axes.
I want to use Labview to control the movement via the 6K2 and to take measurements with hot wires.
Can you help me to control the 6K2 with the labview (using RS232)?
Your help will be appreciated.
Thank so much in advance.
Hachimi (f_hachimi@yahoo.fr)

[Dennis_Knutson]

duplicate post

[McCarty]

Hello Hachimi,

It sounds like you are looking to do standard serial communication with a third-party instrument.  I suggest you look at the Basic Serial Write and Read.vi and Advanced Serial Write and Read.vi shipping examples (found in the NI Example Finder under Hardware Input and Output>>Serial).  You may also want to look at the following serial communication resources:

Serial Instrument Control Tutorial
https://knowledge.ni.com/KnowledgeArticleDetails?id=kA03q000000x1jtCAA&l=en-US


Best Regards,
T. McCarty