12-05-2011 02:30 PM
I've been trying to create a sine wave between 0 and 10 volts on an NI 5412. I've encountered 2 problems and I have one question:
1) I can't generate a waveform with offset, even when using NI examples.
2) The amount of offset I can set the device to is +/- 25% amplitude range. Do I have to create an arbitrary waveform myself?
3) In the brochure it says I can get 12v peak to peak. Does that mean it's between -6 and 6, or is it between 0 and 12?
I would appreciate it if I could see an example.
Solved! Go to Solution.
12-06-2011 12:04 PM
Did you check to make sure that the osciliscope you are using is not set to AC coupled? This device can have a DC offsett of 1.5 V which is 25% of 6 V. So the best you will be able to do is -4.5 to 7.5 V. The peak to peak means -6 to 6 V. I hope this helps!
12-07-2011 11:29 AM
I need to make one correction to my previous post. The offset is +/- 25% of the range. However the max output of the card is 6 V. So, the signal I mentioned in my previous post would actually be cut off at 6 V and would result in a signal from -4.5 V to 6 V. This topic is discussed in page three of the following manual.
The examples related to this device can be found by opening the NI Example Finder and going to Hardware Input and Output>Modular Instruments>NI-FGEN. For your application the Fgen Fucntion Generator.vi under Demos would be a good starting point. Let me know if you need additional help with this topic.
01-09-2012 01:16 PM
Hi, several notes:
1) The peak to peak voltage is 12V. For example, it can operate between 0-12V.
2) The 25% offset limit is for a given wave. That means assuming it is creating a wave, it can only offset it 25% of the range. The solution is to create an arbitrary wave (for example a sine wave between 0 and 10 V) and have the function generator create that instead of trying to offset a sine wave.
Thanks for the help though.
01-10-2012 11:43 AM
You are correct that the 5412 has a peak to peak voltage of 12 volts. Peak to peak values are specified based on the amplitude of the waveform. This is different than the maximum voltage the device can output relative to the ground source it is referencing. The maximum voltage that the device can output relative to the ground the device is referencing is +6 Volts. If your application simply requires a sine wave with a peak to peak voltage of 10 Volts than creating a custom waveform as you described would work. However, the maximum DC offset you would be able to use would be 1 Volt. If you use more than 1 Volt with a 10 Volt peak to peak sine wave than some of the wave would be cut off. To demonstrate this I set up a 5422 Arbitrary Waveform Generator that has the same maximum voltage value as the 5412. I configured the 5422 to output a 10 Volt peak to peak waveform. I then moved the DC offset to +1 Volts. I acquired the outputted sine wave on 5152 Digitizer. Attached is the signal that was acquired from the 5152. You can see that the signal is cut off around +6 Volts. Please let me know if this was a useful demonstration or if you have any more questions.