VI bogging down with Simulate signal running and 2 DAQ assistants, help???

[Vr6Fidelity]

Labview 7.1, 6062E pcmcia card

So i have this VI, the 2 loops work well seperatley but when both loops are running the whole computer slows down to a snails pace. What did i do wrong?

Here is the VI, im trying to simulate a sine wave on output 0 in one loop, and im recording data from sensors in the other loop.

Im new to "MX" and frankly im mystified by it.

[Vr6Fidelity]

Anybody care to take a look at this?

[McKala[DE]]

Hello Vr6Fidelity,

It sounds like you are just trying to get your computer to process too much all at once.  Do you see the same slow down when you remove the file I/O from your VI? Also, what kind of computer are you using?

Regards,

[Vr6Fidelity]

The computer is a dell laptop that meets NI requirements for the PCMCIA card.

Ive found a happy medium of settings that allow the progam to run, but i have noticed another problem:

Noise, there is a high frequency noise over the top of my 1 hz sine wave. I tried to build a lowpass filter on my output but failed. I was using a 2.2mfd capacitor and a 10k ohm resistor. These are the values a calculated for a cutoff frequency of 10 hz. I used the formula in the SCB-68 users manual.

I read some posts about it, and some of them said there was a typo in the scb-68 manual about where to place the components. Can anyone shed some light on how to do this for me?

I believe the noise in the output if from the reading of the input channels. Frankly im VERY dissapointed in the isolation within this card, for more than a grand i shouldnt have to be soldering up filters on a simple sine output. All my inputs are differential.

Soooo, who knows how to build a lowpass on the analog output??

[McKala[DE]]

The noise is most likely due to the environment or the wires you are using, not from the actual signal generated from the DAQ board.  To reduce noise, you should use short, shielded cables.  You might take a look at the the Field Wiring and Noise Considerations tutorial to help you reduce the ambient noise on your signal and here's the online KnowledgeBase with the Lowpass Filter information as well. 

Regards,

[Vr6Fidelity]

I love the "standard answer" the ni people give out. Surely the user must be at fault because the products are perfect. Riiiiight.

I have no cables! I have wired the output directly to a Tektronics scope. I have tried the inputs using the actual cables to the sensors, with nothing on the terminals, and with resistors across the terminals.

the board has noise on the output while it is outputting and reading channels, there is no debate. When i only output there is no noise at all. When in also reading the Ai channels there is noise.

Thank you for your link to the filter KB though. It is quite different than the printed manual.

Does the capacitor go in the red shaded area? im diff on the Ao.  

[McKala[DE]]

Why do you feel like you need to be rude?  I'm just trying to help you out.  Yes, the red is the capacitor.

[Vr6Fidelity]

Sorry if i came off as rude, more like irritated.

So how bout a Diagram for the outputs? your filter link is for inputs and the breadboard area is different on the outputs section.

Am i using the right capacitance value?

[AnalogKid2DigitalMan]

Generic 3dB point for low pass filter equation:

fo=1/(2*PI*R*C)

fo in Hz

R in ohms

C in Farads

For 10 Hz using 10Kohm, C=1/(2*PI*10E3*10) = 1.59E-6F (1.6uF).

Resistance/Capicitance of load may alter 3dB point

[Vr6Fidelity]

Now, if only i could figure out where they go....