How to set up breakpoints with a linear position sensor with a PCI-7344

[Daaf]

Hi,

I'm trying to set up a scanning algorithm for a Nanonics 3D piezo stage, which should synchronize with a counting card (PCI-6602) using breakpoints on the motion card (PCI-7344). The Nanonics stage has two position sensors (just for x-y) giving me a linearly varying voltage depending on the position. Nanonics connected these sensors to the first two analog inputs of the motion connector of the motion card.

Now I'm planning to use breakpoints to synchronize the stage scanning to a counting card (probably using an RTSI cable), but I got the impression that this can only be done by using the encoder inputs of each individual axis, not by using the analog inputs. Could someone comment on that? Explanations or tips would be greatly appreciated, many thanks.

Kind regards,

Daaf

[Kristoff2]

Daaf,

Do you want to use the analog outputs to trigger DAQ tasks such as counters or use them as analog feedback for motion control?

Regards,

Sam K

Applications Engineer

National Instruments

www.ni.com/support

[Daaf]

Hi Sam,

I'd like to use the analog inputs to trigger DAQ tasks (counting). Control loop feedback would be great but I think we can calibrate our stage sufficiently to get it working decently. Thanks!

Daaf

[Kristoff2]

Daaf,

If you want to tigger DAQ tasks it would be best if you could wire your trigger directly to your DAQ card.  If this is not an option you can use signal routing and a RTSI cable to pass the signal from your motion controller to the DAQ card PFI line for triggering.  You may experience some small latency in this case.

Regards,

Sam K

Applications Engineer

National Instruments

www.ni.com/support

[Daaf]

Hi Sammy,

So I've been working on it some more, and still cannot get the breakpoint to trigger on the analog feedback from the stage (wired to the analog in port of each axis). Eventually I'd like to use these analog in ports on each axis as a feedback for the stage position, but I also need to synchronize my stage movement with DAQ tasks (through RTSI or the PFI lines as you mentioned). I noticed in the help file on the "Set Breakpoint Output MOMO.vi" that breakpoints can only trigger on encoder inputs. Is this true or can breakpoints trigger on analog feedback as well?

Also, the scanning will be done at about 10 lines per second, and we'd like to make sure that there is reliable synchronization, so as far as I can tell writing an onboard program that manually performs a 'breakpoint' would be too slow. Any suggestions?

Thanks,

Daaf

[Z'atari · Accepted solution]

Hey Daaf,

I believe this answers your question.

Regards,

A. Zaatari

[Daaf]

Thanks, I found that document just after posting but was hoping for a different solution.