02-18-2012 12:10 PM
I want to know about the accuracy of PXI 4110 DC power supply. I have to use PXI 4110 to apply a voltage sweep from -2.5v to 2.5v with a 0.5v step using Labview, How can I do it?
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02-21-2012 09:33 AM
The specifications for the PXI 4110 can be found here. The first table on page 2 outlines the voltage output accuracy and resolution. Looks like the 4110 has 0.12 mV or 0.40 mV precision depending on the voltage range. The accuracy changes depending on the temperature and the voltage being outputted so you'll have to calculate that based on your voltage ranges.
For programming in LV, there are examples that help outline programming with the DC Power drivers. The examples can be found in LV at Help >> Find Examples. Then, navigate to Hardware Input and Output >> Modular Instruments >> DC Power. I would check out these examples to get an idea of how to program DC Power in LV.
Also, it appears that the available voltage levels for the 4110 do not include a level which will cover from -2.5V to +2.5V, so you may have to set up the VI to sweep from -2.5 to 0, then close and restart the session to sweep from 0 to 2.5V.
Hopefully this helps.
02-21-2012 10:37 AM
After reading through my post, I realized I should probably be a little more clear on that last paragraph...
The available voltage ranges for the PXI-4110 are different for each channel as shown in the first page of the specifications:
Ch0: 0 to +6V
Ch1: 0 to +20V
Ch2: 0 to -20V
So to create a sweep from -2.5 to 2.5 V, you will need to use multiple channels. You would use Ch2 to sweep from -2.5 to 0V. Then you can use either Ch0 or Ch1 (Ch0 would be better since you'll get better precision) to sweep from 0 to +2.5V. There is a good example called "NI-DCPower Software-Timed Two-Channel Voltage Sweep (IV Curve).vi" that does almost exactly what you are looking for.
Hopefully this clarifies it!
02-22-2012 07:44 AM
Hi Chris G,
Thanks for your response. I searched for the example "NI-DCPower Software-Timed Two-Channel Voltage Sweep (IV Curve).vi" but i could not find it. Would you help me how can i get it.
02-23-2012 12:21 PM
In the NI Example Finder with the Browse tab selected navigate to the folder location: Hardware Input and Output >> Modular Instruments >> NI-DCPOWER (DC Power Supplies) and the example should show up here. What version of LabVIEW are you using? The actual file location on your computer should be something like:
C:\Program Files\National Instruments\LabVIEW 2011\examples\instr\niDCPower\Single Point
(assuming C: is your system drive and LV 2011 installed in the default locaion)
Do you have the DC Power drivers installed? If not, you can download the latest version here. When you go through the installation of the driver, it should automatically install LabVIEW support if you have LabVIEW on the computer. However, you can confirm this during one of the steps of the installation. Make sure that LV support is being installed. Also, if you have an old version of LV you may have to use an older driver version that is compatible with that LV version. Check the ReadMe files for LV and device compatibility.
Hope this helps,
02-24-2012 06:59 AM
Hi Chris G,
I am using LV 2009. I could not find the example in the folder "C:\Program Files\National Instruments\LabVIEW 2009\examples\instr".
02-27-2012 04:45 PM
Do you have the NI DC Power drivers installed? It sounds like you may not, or that LabVIEW support files were not installed when you did install the DC Power drivers. You can check to see if you have the drivers in MAX by expanding the Software tree in the lefthand pane.
If you do not have the drivers, download them from the link posted earlier and install the drivers. If you do have them installed, try doing a repair of the driver install and ensure that LabVIEW support is being installed. This will be one of the steps in the installation.
Hope that helps,