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Pxi 4130 channel 1 output led red

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Hi, I need help with my SMU - PXI 4130 - the red light on channel 1 output is allaways on, during my measuremnet.

Is that even correct, or does that mean 'ERROR'?

And where do I find that information, i was looking on ni.com, but did not find the right pdf.

 

Hope somebody can help me with that one - Thnx a lot.

 

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Generally speaking, the LED will be red if the channel has been disabled due to an error. However it sounds like you're seeing this behavior and are still able to take measurements on channel 1, is that correct?

 

One possible cause for the channel being disabled is the over-temperature protection being tripped if the PXI-4130 is sinking power levels beyond the rated specs (10W at <30°C).  Do you know whether the instrument is sourcing or sinking power when this happens?

 

Does the NI-DCPower driver return any error messages after you  see the red LED?

 

The manual you are looking for can be found here:

http://digital.ni.com/manuals.nsf/websearch/3E60160974292CB6862575E40053D50A 


Jeremy
National Instruments
Power Supplies & SMUs
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Accepted by topic author labview_vr

Is it red or amber? Using the link for the NI DC Power Supplies and SMUs Help that JeremyDC gave and navigating to Devices >> NI PXI-4130 >> Front Panel, you can see that amber would indicate that you're operating at the current limit, or in "compliance" (Help file >> Fundamentals >> Compliance). This just means that you have hit the maximum current allowed (the current limit) before reaching the requested voltage output. It's not an error, but a built-in feature of SMUs.

 

You may just need to allow a higher current limit if you want to get to the requested voltage output, or you could increase the resistance of the DUT in order to limit the amount of current that flows as a result of the requested voltage.

 

I hope that helps! 

Mark E.
Precision DC Product Support Engineer
National Instruments

Digital Multimeters (DMMs) and LCR Meters
Programmable Power Supplies and Source Measure Units
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Hi

 

i am facing the same problem I see a red light in my PXI 4130, however the SMU works fine, i can read the values of a known resistor. However, when i set my compliance value lower on purpose, just to deliberately lead the SUM into compliance, surprise, the led turns GREEN, although the SUM is indeed in compliance... So, somehow the colors are swapped... Can that be? Is there an easy fix for that?

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Hey Marianito,

 

The color of the front panel indicator is determined by a red and a green LED that are cast into the same package, which is then placed onto the 4130 PCB.  Each LED is controlled by a separate driver circuit.  To get amber, both LEDs turn on at the same time.  Since LEDs only emit light when forward biased, there is no incorrect way to mount the LED onto the PCB and still get both red and green light (either red, green, or both colors would be absent).  If this is a hardware issue, it would mean that the LEDs would have to be swapped inside the die on the chip we place on the board.

 

Once you've verified that the 4130 is within operating temperature, I recommend disconnecting everything from the 4130 and setting the output to:

-constant voltage mode at 10V/10mA to verify the LED is green

-constant current mode 10V/10mA to verify the LED is still green

then short HI to LO set the output to:

-constant current mode 10V/10mA to verify the LED is amber

-constant voltage mode 10V/10mA to verify the LED is still amber.

 

If you're using the AUX power supply, try the same test again with the power supply removed.

 

Let us know what you find.

-John Sullivan
Problem Solver
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Strange

 

open terminals

constant voltage mode at 10V/10mA --> LED is green, no compliance sign and CV iluminated

constant current mode 10V/10mA --> compliance indicated in the control pannel and CV iluminated as well (should be CC?), but LED is still green, should be red...

 

short terminals

constant voltage mode at 10V/10mA,   LED is red, compliance and CC iluminated

constant current mode 10V/10mA , LED is red, only CC iluminated , no compliance --> Led should be green

 

Something is messed with the LED i would say...

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Hey Marianito,

 

Observations on your last post:

1: The LED should be amber, not red.  To verfiy whether the color you're seeing is red or amber, plug in the AUX power supply, short ch1 HI/LO together and then set the 4130 to output 2A@1V.  Then unplug the AUX power supply from the 4130.  Both the AUX and CH1 LEDs should turn red and the soft front panel should have an error.  Is the color you observe here the same as the color you observed in your last post?

 

2: The ch1 status LED should always be green when the power supply is in constant voltage mode.  Note that even when you've set the supply to CV mode, if you hit the current limit, the supply will enter CC mode.

 

3: The ch1 status LED should always be amber when the power supply is in constant current mode.  Note that even when you've set the supply to CC mode, if you hit the voltage limit, the supply will enter CV mode.

 

4: Using 2 and 3, the output behavior should be:

open terminals

constant voltage mode at 10V/10mA --> LED is green, no compliance sign and CV iluminated

constant current mode 10V/10mA --> LED is still green (correct because we're forced into CV mode), compliance indicated in the control panel and CV iluminated as well (we are in CV mode because we've hit the compliance voltage).

 short terminals

constant voltage mode at 10V/10mA,   LED is red, compliance and CC iluminated

constant current mode 10V/10mA , LED is red, only CC iluminated , no compliance.

 

5. It appears your 4130 is operating normally.

 

Please let us know if you have any questions about the above explanation.  More detailed information can be found in the DC Power Suppies and SMUs Help (located on your computer if DC Power is installed).  Once open, search for "Constant Voltage Mode", "Constant Current Mode" and "PXI-4130 Front Panel" for more information.

-John Sullivan
Problem Solver
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