11-27-2007 04:18 PM - edited 11-27-2007 04:18 PM
11-27-2007 04:42 PM
The easiest thing for you is to use the DAQ Assistant. Drop it on the block diagram and when the wizard starts, select Acquire Signals>Analog Input>Current. You'll then select the device and channel. The next screen will show the configuration and have a box for the value of the external resistance. You also have a Connection Diagram that shows you how things should be wired but unfortunately, the BNC 2120 is not one of the supported terminal blocks. It's pretty easy to figure out though. You just need to wire the resistor across the differential inputs.
When you are done, click the OK button on the assistant and you have a ready made VI that will return a current reading whenever it is called. You can also create an assistant for the voltage output.
11-27-2007 09:20 PM
04-22-2011 09:44 AM
Is it possible to measure AC current in this way? Thanks.
04-22-2011 11:01 AM
Physically it's the same. But, you'll have to collect multiple samples that include at least one whole cycle of your input waveform and do the math in software to calculate AC current.
http://forums.ni.com/t5/Multifunction-DAQ/Determine-AC-Current-through-DAQ/m-p/803538
Or you can do it the easy way with a DMM connected to your PC beinf read by LabVIEW.
04-22-2011 11:41 AM
Thank you for your prompt reply.