I would like know if PCI-7344 performs electronic camming (not only gearing)

[marco_engenheiro]

Hello. I would like know if PCI-7344 Stepper/Servo Motion Controller performs electronic camming. I know it executes electronic gearing but I need it does a advance/retard move (camming) in my application. When I try to use the PCI in this way a error shows up. 
 
Thanks for any help

[Jochen]

Sorry, but this mode is not supported on a PCI-73xx device. The reason why you find these functions in NI-Motion is the fact, that it is currently only implemented for NI SoftMotion Controllers.

Kind regards,

Jochen

[marco_engenheiro]

Do you mean there is not a PCI-73xx does such function? What do you propose? So, should I use NI SoftMotion Controller for Copley CANopen? 
 
thanks

Marco

[Jochen]

Marco,

that's correct. 73xx boards don't support camming. So if you need to synchronize arbitrary moves to a master encoder or axis, NI SoftMotion Controller is one option. Another option offered by NI is the NI SoftMotion Developement Module. This module is based on NI realtime targets like cRIO. Please have a look at this thread for more information.

Regards,

Jochen

[marco_engenheiro]

Thanks Jorken for the information. By the way, I think would be interesting to explaining about my application. Maybe there is possibility to use gearing instead of camming. 
It works like this: 
It is a winding coil machine. One axis (master encoder) moves the coil in rotation (always in the same direction) whereas other axis (slave stepper) accomplishes scattering moves of wire (in a constant advance/ retard move). The process finishes when all layers are complete. So, it seems as if it were two distinct gearing move (same gear ratio absolute value but with change of direction only (positive or negative gear ratio)).

Thanks again,

Marco

[Jochen]

Marco,

this type of motion can't be accomplished with gearing, but there are some other approaches I can think of. The most promising approach could be Contouring. In this mode you can calculate an array of position data for both axes and download it to the controller. This allows you to define the exact positions for both axes at any point in time. For two controlled axes this is typically a good alternative to camming. Please refer to the shipping examples of NI-Motion for more information and let me know if this works for you.

Jochen

[marco_engenheiro]

Ok Jorken but I don't understand how I do this with master axis because it works with a AC motor. Now, I am using a encoder to command other axis. 
 
Thanks, 
 
Marco

[Jochen]

Hi Marco,

I see. So unfortunately in this case I don't see a reasonable way to accomplish this task with a 73xx board. My suggestion works only if you can control both axes with the 73xx. Thus the only thing that I can recommend to you, is using the NI SoftMotion development module, as mentioned before.

Jochen

[marco_engenheiro]

Thanks Jochen. I will see how it works. One doubt: Do you have any ideia about financial cost and project cost (development time) approximately? I'm sorry for wrong spelling of your name. 
 
Thanks again 
 
Marco

[Jochen]

Marco,

the answer to your questions is: It depends.

I can't tell much about the financial side of things. If you own a developer suite, all required software components should be already available to you. If not, upgrade prices depend on your existing licenses and on your personal environment (e. g. industrial or academic). On the hardware side the cheapest setup could be done with a standard desktop PC that supports LabVIEW Real-Time and a multifunction DAQ board. Other options are cRIO- or PXI-systems with or without FPGA programming.

Please talk to your local NI sales representant about your options.

Of course NI-SoftMotion is more complex than using a ready to run motion control board. On the other hand it took me less than three hours to get a servo motor up and running (including cabling), when I first started with NI-SoftMotion, but of course I have a decent level of LV RT and motion control experience and I have learned, that using NI-SoftMotion is not trivial for beginners. Still R&D has done a good job with SoftMotion and the shipping examples and they are currently working on a new version, that will simplify things much more, but this will be part of a new release sometimes in 2009 and I can't talk more about that by now.

In general with SoftMotion you get access to every aspect of a motion controller, including the trajectory generator, the spline engine and the control algorithms. On the other hand you also need to become familiar with these terms to a certain level.

I hope that helps,

Jochen