georgekm

OK, problem solved. Thanks guys.

Hi all,

I'd like to programmatically control the display precision of an array of indicators.

When I use a property node on the array to access an array element, it seems that the array abstracts the element (and I can no longer use a property node to conrol precision of the element).

If anybody has any ideas or solutions, they would be greatly appreciated.

Hi all,

Does anyone know how to control the color of (or simply remove) the grey container that holds the XY plot & the scales?

I'm asking because I want to be able to print out a copy of the front panel (or maybe an .html report with an included image of the XY plot), and the big grey container box is not condusive towards making nice prints.

Thanks

Setting the tabbing order seems to do the trick. Thanks Chip!

Hi all,

I'm using Control Value: Get All [Variant], a method of the VI class. The method returns an array of clusters. Each control in the VI is represented by a cluster (of two elements: the name of a control and it's associated value expressed as a variant). The clusters are contained in the 1D array.

The only problem I'm having is that I'm not sure how to reorder my controls in the array. They seem to be ordered based on the order that they were added to the front panel of the VI. Unfortunately, this isn't the order I would like them in, and I want to avoid having to programmatically manipulate the array to order them properly. Is there some way I can change this order without either 1) going in and replacing all the controls on the VI in the desired order, or 2) programmatically manipulating the returned array?

Thanks for your time

Cool! Using the counter input worked. Thx a ton.

George

QUOTE (georgekm @ Jun 16 2008, 08:44 AM)

Cool thx!

Lemme try what you say. I need to use the encoder signal as a trigger to collect data too. Hope that spossible with a counter.

George

QUOTE (georgekm @ Jun 16 2008, 08:44 AM)

Cool thx!

Lemme try what you say. I need to use the encoder signal as a trigger to collect data too. Hope thats possible with a counter.

I tried unbunling the waveform output but am running into the same data type compatibility issues. Whats the deal with these waveform outputs? I can't seem to do anything with them...

George

Cool thx!

Lemme try what you say. I need to use the encoder signal as a trigger to collect data too. Hope that spossible with a counter.

George

QUOTE (Neville D @ Jun 12 2008, 03:10 PM)

Apart from a very snazzy icon, you seem to have done little else!

Like I said before use a counter for measuring frequency, not a digital line. Look at the examples on counters in LV and search the NI website for "reading counters" or "reading encoders". There is some info there to clean up signals as well as using quadrature encoders.

This is quite critical for a real-world application since, noise is very likely to corrupt your encoder signals, and using these techniques you will count the correct transitions of the encoder pulse (avoid reverse counts), and avoid missing pulses.

As to your specific question: you can use an unbundle node on your digital waveform and that should give you:

* the Y array of digital data

* t0 the start pt

* dt the time between successive pts.

Then you can do whatever processing you want on the array; though I would imagine you just need to count the number of high values (N) and divide by (dt*N), so I don't really see the need for a "signal processing" VI..?

Neville.

Hello,

I'm using a PCI 6221 DAQ Card. I am reading in an encoder signal through one of the digital inputs (PF1). The output is a 1 D arrray of digital waveform and the Signal processing VI won't take it in as an input. Code is attached.

Thanks!

George

QUOTE (Neville D @ Jun 11 2008, 01:12 PM)

What hardware are you using? what is the frequency of interest? Show us your code.

I would use a counter channel to measure frequency. Look at examples for counters.

Neville.

Hello,

I am trying to get the frequency of a digital signal. I used the DAQAssistant to collect N samples off a digital line. The outpiut data format is a 1 D array of digital waveform. I cannot connect it to the Signal processing VI since it needs to be in the 'Dynamic data' format. Using the 'Convert to dynamic' Vi does not work either. How do you process a digital signal?

Thx.

Thx guys,

I figured out the mistake I was making. I had two DAQmx read VIs trying to access the same channel at the same time. I've now wired the error out from one read vi to the next one so that the two activities are performed one after the other.

ge

Is there a way to read both digital and analog signals in the same VI? I have an encoder line that is used as a trigger for aquiring data from an analog input. But I also want to be able to plot the encoder signal. Is there some way to do this?

Thx