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6430 cannot apply negative voltage! please HELP US!!!

Posted: November 12th, 2019, 2:26 am
by KeithM
Hello everyone,

We meet a problem when using 6430 to output voltage and measure current: the 6430 can not output the negative voltage or read the negative current.

We googled our problem and found some related issues and solutions in this forum:(viewtopic.php?t=138779)(viewtopic.php?t=140112)(viewtopic.php?f=15&t=117880&p=217127&hi ... on#p217127), but none of these procedures solved our problem.

Then we began to calibrate the machine according to the 6430 manual. However, we found a worse problem when conducting the calibration:
The 6430 had a horrible shift in voltage calibration section! We use another 6430 serve as multimeter, and the result was:
Source range: 0.2V;
Source voltage -- Multimter voltage readings
+200.00mV -- 0.209V
+000.00mV -- 0.122V
-200.00mV -- 0.104V
+000.00mV -- 0.094V
Also, an error +507 or +508 was shown at the end of -200.00mV section.

However, we didn't meet this horrible output voltage shift when using Labview to control it.

Does anyone know how to handle these issue? Please help us! We really don't know why this machine can not apply negative voltage nor behave weirdly during calibration.

Re: 6430 cannot apply negative voltage! please HELP US!!!

Posted: November 25th, 2019, 5:28 am
by Andrea C
I'd be interested to know more about how you are connecting to the 6430 and the triax connections.

For the validation of unit#1 using a second 6430, the connections and settings on unit#2 would be very important. Connecting two SMUs directly together can give you strange outcomes if you do not fully understand output off behavior, etc.
Best if if you can get a simple volt meter or DMM in DC volts mode to act as your validation tool.

If you have the small triax to three alligator clip cable, put that on the HI triax and have the SMU source a Voltage/turn blue light on.
On the compliance, anything flashing?
With DMM, measure the voltage between the red and green alligator boots. The black boot should be floating/not touching anything conductive.