voltage analyse

[jjv]

Hi everyone!!

I´m such a new user with labview and I want to know how I can chance the voltages of measurements to the right form. I have two signals and two channels. The measurents are force (channel 2, y-axis) and distance (channel1, x-axis) and I going to use the xy-graph. I know also the the voltage ranges what the sensors would give and I have the formulas what I want to use. So how I can moves the voltages to the righ form using by formulas?

[dpacaba]

Hello jjv:

You should add inputs and outputs to your formula node. The raw data will be connected to the input while the output will be connected to the xy graph.
For simple mathematical operations, I would rather suggest the functions from express numeric palette though.
I hope this helps. If you have any other questions, please don't hesitate to ask.

[jjv]

Thanks for your advise Debonair!!

Now the formula works correctly...
Still I´m not so sure that would it measure voltages without formulas...
It looks like that it measures only amplitude...Because the range what it measure is so high
and it moves fast.

Do you know also how I can use the voltage trigger...
Program would start only then when a certain voltages is
given.

[dpacaba]

Hello jjv:

I am very glad to help.

The range setting can be configured on "DAQmxBase Timing.vi". In your program, you placed a control on the "Samples per Channel" and "Rate" inputs. If you placed a high value on "Samples per Channel", then it would acquire more samples. If you placed a high value on "Rate", then your acquisition would be faster.

You can set the voltage trigger using "DAQmxBase Trigger.vi". You can set it to start on analog edge, although not all hardware supports this kind of triggering mode.

[jjv]

Thanks for the advise Debonair!!

Only problem what I have now is that this program
not measure the voltages right now...!?!? I´m using NI USB-9215 device and
I have two anolog signals and I want moves the signals in the xy-graph...as you already know.
And in xy-graph I need only a one line what shows the data of sensors...Y-axis shows the channel 1 and x-axis shows channel 0...now it would gives too much information...Because the process what we use is very simple and the data
points amount is not so high, only 100-200 per second...What you think about present
program what I have add to a file??

[dpacaba]

Hello jjv:

I would rather advice a few things, please try if these would work...

1] Add a string constant in the "Name to assign" input for the "Create Virtual Channel" for Physical Channel1. Have the same string also as an input to "Source" of the "Start Trigger"
2] The trigger level should be at 0-10V. I would rather suggest that you would have a separate control for the said input.

Please see my attachment. Please inform me if you have any more comments.