Buffered high-speed capture with multiple axes

[IanC_]

Graham, Jochen,

Many thanks for your input.

I think there's an acceptable workaround.  If necessary I can get away with having position data at a low rate (down to ~20 Hz), so either using an onboard program or polling for positions should be OK (if not ideal).  If that fails I'll look into the 6602 board - thanks for the tip.

BHSC just seemed like a really good solution: neat code, not too CPU-intensive, jitter-free timing, and can be synchronised with the rest of my DAQ operations.  I'm a bit surprised it doesn't seem to be more commonly used, but will look forward to a future NI-Motion update!

Cheers,

Ian

[GrahamG]

Hi Ian

I'm glad that you have an workaround that at least has the functionality even if not the desired speed. I will stay in contact with R&D and if they find a better solution I will get back in contact.

best regards

[KostasB]

Hi Ian,

A quick update, R&D is still working on this problem;  it has not been resolved yet.  We will let you know as soon as it is fixed.

Best regards,

KostasB

NIUK Applications Engineering

[2photonGuy]

hi all

I have this problem with initial operation mode setting.
For a single axis I have a written a code for 1d motion for jog shuttle using RELATIVE POSITION as operation mode.
For the same axis I have written another code for space shuttle joystick using VELOCITY as operation mode.

Now I want to combine both the codes so that I can switch from relative position to velocity.
Is it possible.

Thanks

[Robert_Lee_NIUK]

Hi,

 As you've posted on an old post, only the original posters may get communcaition of this new addition to the thread. I'd reccomend starting a new thread and linking back to this one using a link.

With regards to your problem though, is it with the same system or are you using another card?

[2photonGuy]

Hi

Well I have the card 7350 installed via which i control mz motors. Now i need to create a labview program that allows me to control the stepper motors and switch between the velocity and position mode which is important for my experiment as it involves micrometer precision.

Now position mode is beneficial for me as i can save a position and move back to it anytime during my experiment.
Velocity mode helps me to operate things at diff velocities: high and low.

Well, it switches nicely from position based control to velocitz based control but I was having probs in switching back to position mode. I have worked arount that.
Here is my solution:
Everytime u switch mode. A trigger is sent to case structure, which [haults the current motion(if any)-sets operation mode to position control-"runs search reference and immediately haults it"] and then when i use my position control ...It works 🙂
 I reallz dont know what this find refernce  thing does to my program but my thing works ...finally

[Robert_Lee_NIUK]

Hey,

Thanks for getting back, it's always good for customers to let us know when they have a working solution! the problem may be the de-allocation of the hardware resources, and by implementing this method it looks like you gave the system enough time to unload any resources from the previous velocity motion controls

[2photonGuy]

Hi

That actually is not the correct solution. Running reference move and then halting it can be disastrous.

The mistake in my program was everytime I ran velocity override thing I was not bringing it back to 100% when m done with velocity control. So the next time it runs in the position mode when velocity override is 0 there is no effect of loading a new velocity.

Hence bring the velocity override thing to 100 once u complete ur velocity operation mode in case you are using the velocity override thing.

Thanks

[KostasB]

Hi Ian,

I am glad to announce that R&D released the patch that fixes this issue. I will send it to you via e-mail. I apologise for the time it tooks us to solve the problem but it should be all good now.

KostasB

NIUK Applications Engineering

[IanC_]

Hi KostasB,

That's great news - thanks for following this up for so long and keeping me informed.  I look forward to trying the fix.

Ian