multimeter not reading powersupply reading

[SDP22]

Hi,

I am new to labview and have been learning it since few days. I tried to write a small code where I sweep the voltage at power supply (Agilent, E3645A) and display the same thing to multimeter (34405A). I have connected multimeter to computer using USB and power supply has GPIB which is converted to USB and is connected to computer. And, I have connected multimeter and power supply by banana-banana cable.

When I run the code, I can see that the voltage sweep has been recorded in a txt file, and I believe same voltage should have been recorded in multimeter output as well but it is not working. Neither the display in multimeter shows the output of power supply nor it can record it. Am I missing any thing in my code? I have attached my code along with it.

Thank you

[Dennis_Knutson]

Bad, bad idea to use the Stop function. If you actually had any errors, they would not be processed. Terminate the while loop the correct way and try again.

You can also easily open up the dmm read and ps set voltage functions and see if either or both are working.

[SDP22]

Both of them are working independently. The problem arise when I connect multimeter and power supply. I removed STOP and kept it as a condition for while loop. Still the problem is sam. I have attached new VI and its txt file. So, txt file should have same value on both columns. First column records sweeping of power supply and second one should had the reading from multimeter

[Dennis_Knutson]

Now you got rid of the error handlers. Why? You also don't have any data dependency between the voltage step and the voltage read. That would not cause an error it's just that you cannot associate a voltage setting with a voltage read.

[SDP22]

Dennis - I did not understand what do you mean by "You also don't have any data dependency between the voltage step and the voltage read." If you can clearify me a little bit. Now I have error handler but still the problem is multimeter not being able to read power supply.

Thank you!

[Dennis_Knutson]

It's really basic understanding of LabVIEW and dataflow. The read function might happen before or after the set function. Simply placing the read function to the left of the set voltage function does nothing to ensure execution order. You would wire the error out of the set voltage function to the error in of the read voltage function. Then you have enforced execution order with data flow,

Set a breakpoint or right click on the read function and change the SubVI Node Setup to show, close, and suspend so that you can see what the read function is doing.