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controlling LCR and power supply using 1 VI

I want to measure capacitance for of diode for voltage sweep from -5 to 5 using the hp 4284 LCR meter. I am applying voltage using the hpE3631A DC power supply.

I want to take the capacitance measuremnt few mili seconds after the voltage is applied, how can I do that?

The VI that I have now gets stuck when I try to run it. What could be wrong?

I am attaching the VI voltage_sweep_try.vi and sub VIs (configure_output.vi and continual measurement.vi)

Message Edited by what is this thing on 03-25-2005 06:21 PM

Message Edited by what is this thing on 03-25-2005 06:21 PM

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What do you mean by getting stuck? It won't stop when you press the Stop button because the button terminal is outside the loop. The only value of the button available to the wiring inside the loop is the value which was present when the loop started executing. This is fundamental to the dataflow paradigm of LV.

The only way to get millisecond timing is to do the triggering in hardware or to use a Real Time system. Most instruments take 50 ms or longer to respond to a command and the OS can occasionally take that much or more time to do whatever it wishes.

At some point you may wish to put some error checking on your Start, Stop, and Step voltages. If Step happens to get set to a negative voltage, the loop would never stop.

Lynn
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Thank you very much for your help.

I mean when I press start button, the VI never gets completed. It haults somewhere. Although when I pressed stop, it stops!

Thanks for your reply.

I have one other questino though.

Could you please have a look at the case structure in the voltage_sweep_try.vi. I want to do the following.

I am configuring the voltage source, when the voltage inputed to the VI inside the case structure is greater than or equal to zero then the voltage limit is set to +25 and when the voltage source is negative then the false part of the case structure should execute where the voltage limit is -25.

It seems correct to me but when I run this VI say from -5 to 5 volt with step of 1V, it gives me error for all the negative inputs and runs smothly after 0 volt. (This is only if i remove the bottom part of the VI, ONe which is taking the capacitance measurement)

What did I do wrong??
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