Doubts using NI cRIO 9012 and NI 9111..

[M_Silva]

Hello.. i'm using NI cRIO-9012, NI-9111, NI 9234, NI 9201 and NI 9474 in a school project... i started to do some easy things like sine wave acquisition in order to be more in touch with the labview hardware and software, the software that i'm using it's the LabView 2009 Service Pack 1.

i have acquired the sine wave with NI 9234 and NI 9201 and i couldn't find the diference between this two modules, is there any thing that i can do with one of them and couldn't do with the other? what's the main diference between them?

i couldn't realise either how many points am i acquiring at each period (acquisition rate i think) of the wave? (would you like me to send the code?)

from these two modules i got something, from the NI 9474 i've saw nothing yet... i was trying to generate PWM wave and i use the FPGA help wizard to generate the code, everything was fine but i couldn't get anything.

I hoping that someone can help me..

Thanks

Mário Silva

[ElRambo]

Hi M. SILVA,

The module NI 9234 is a specific module made for smart sensors, it means that it can provide an excitation voltage for sensors like accelerometers, etc...whereas the module NI 9201 is a simple analog input module.

You can get more informations about these two modules here :

http://sine.ni.com/nips/cds/view/p/lang/en/nid/208802

http://sine.ni.com/nips/cds/view/p/lang/en/nid/208798

Also, for you other issue, I would advise you to join your VI in order for us to help you. I don't understand what's going wrong now, so if you could post your application this would be useful.

Thanks for all !

Have a nice day !

Regards,

[M_Silva]

Good morning Maxime,

thanks for answering my question. My application as to do with a IGBT module controler for an Electric Vehicle.

I want to generate a PWM in order to control the IGBT's gates, the final goal is the implementation of a closed loop control...but for now i just want to see a PWM in my scope 😃

i've attached the VI's generated from FPGA WIZARD.. yesterday i tried some VI's from PWM Example by NI and it seems complicated because i couldn't find some blocks..

i have another question, in FPGA Wizard i can implement a PWM with diferent timing engines..wich one would you choose??

Thanks for help

With the best regards

Mário Silva

[ElRambo]

Hi M. SILVA,

I think that you should check if your FPGA VI is really running...Sometimes it happens that the VI is not running but the RT VI is not showing anything about that.

If I were you, I would force the FPGA VI to run once it is open by the VI "Open FPGA VI Reference". You can force the execution of the VI by right clicking on this VI and configuring it to do so.

Also, I didn't see anything wrong with your VIs.

I don't know what you're talking about when you say that your PWM can use different timing engines. I guess your talking about the timing engines you can use in your whole FPGA VIs, the timing engine that will time your timed-loop.

In that case, I would advise you to use the timing engine that has the highest frequency you can use. It depends on the frequency you want to use, generate with your PWM.

Finally, I would advise to have a look at these two examples right here :

http://zone.ni.com/devzone/cda/epd/p/id/979

http://decibel.ni.com/content/docs/DOC-2380

Don't hesitate to ask if you have any further questions.

Thanks for all.

Regards,

[M_Silva]

Hi Maxime,

thanks for answering, i took a look at the links you gave me and one of them i've seen it before (cRIO Pulse Width Modulation) but i must tell you that i'm new at labview and those VI's are too much for me to carry yet 😃 ....

About the engine times i've told my doubt was, should i use Single Point Continuous or Single Point Timed I/O to create PWM??

I tried Single Point Continuous and i'll let you know the VI's i've used...I could see that by changing the values of Active Time and Period the brightness of the little led at the output port was changing too but there was nothing appening at the scope. The signal just change all to zero or all to my source signal (12V), there's no PWM oscillation.

About the code i have some questions too, i can't understand how some subVI's are created, how are they conected with the FPGA and HOST and what are they for..

there are some blocks that appear  when i run the FPGA Wizard that i can't find when i creating a blank project, i think that they has to do with the subVI's i told you and some dependencies too.

I really appreciate your patience, thanks a lot.

The best regards

Mário Silva

[M_Silva]

Hi Maxime,

can you tell me if i have done something wrong in the messages i've posted? cause i had no reply from you (the PWM problem is already solved) neither from other problem i posted..

Thanks for help

Mário Silva