I have a PXI 4140 SMU to apply voltage and measure current. my project is to apply voltage for a predefined time contniously (i.e 30 seconds) and log the measurement durring this time. how can I set the 30 second time? should I create a timed loop? how the singe point voltage source works? does it apply voltage until you stop it or is it apply the voltage for a moment?
I spent some time playing with this this morning, and it seems to me like slightly modifying the NI-DCPower Source DC Voltage.vi in the example finder should be able to do what you need.
If you place the sections of the example before the reset VI in a while loop, and wire the Elapsed Time Express VI to the stop button configured for 30 seconds, it should supply a voltage for 30 seconds as you are needing. Let me know if you have any questions about this method.
Matt W. Applications Engineer National Instruments