Swap DC and ground voltages of Keithley 2400 meter

Hi
I am using Keithley 2400 source meter to apply voltage to my chip. The test that I am performing
has the following requirements:
In the first stage, I apply DC voltage (from source meter) on one pad (Pad-A) of the chip and ground
(from source meter) on the other pad (Pad - B) and take some capacitance measurements.
In the second stage, I need to swap these voltages i.e. DC voltage to Pad-B and ground to Pad-A.
I am already using a labview code to apply the voltage and make the capacitance measurements.
Is it possible by any chance that I can control the swapping with the labview code automatically,
without having to swap them manually?
Thank you for the help

Is it important to switch the GROUND?
Or do you only need to switch the polarity of the voltage between your pads?
Sometimes it makes a BIG difference
Greetings from Germany
Henrik
LV since v3.1
“ground” is a convenient fantasy
'˙˙˙˙uıɐƃɐ lɐıp puɐ °06 ǝuoɥd ɹnoʎ uɹnʇ ǝsɐǝld 'ʎɹɐuıƃɐɯı sı pǝlɐıp ǝʌɐɥ noʎ ɹǝqɯnu ǝɥʇ'

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Programmed vs measured voltage on Keithley 2400 and other things

Hello everyone,
I have two issues with our Keithley 2400, which we control through Labview, and I would be very grateful for some help/advice. The issues are listed below:
1) We use the 2400 for 4-point probe measurements, so we plot graphs of current vs voltage to get the resistance from the slope of the curve. However, when we look up the data generated during a measurement, the voltage sweep values that we program often, but not always, do not match the measured voltage values. For example, what was meant to be 1 V, might actually end up being 1.2 V or maybe 0.8 V, this can be both positive and negative with respect to the programmed values and is not constant. This also leads to the fact that our curves, although straight (so Ohmic conductor), do not go through the (0, 0) point on the graph.
2) Second problem is that we would like to determine what is the time between successive measurements in a voltage sweep. We have tried some example vi files that by default come with the Labview, e.g. Keithley 24XX Read Multiple - SW Trigger or Keithley 24XX Read Multiple. If someone knew how to find the time separation, then we would be grateful. We only have control over the number of invididual readings taken and the timeout, which we guess is the maximum time allowed for the measurement.
Many thanks!

Good Afternoon PiotrW,
1. Could you please provide the code you are using to program the voltage sweeps?
2. You could use the timestamp output of the Keithley 24XX.lvlib:Read (Multiple Points).vi to allow you to find the time difference between successive samples. It should be a simple case of subtracting succesive measurements from each other to find the time difference between data points.
Regards,
Al
Regards,
Al C
National Instruments,
Application Engineer

How to set the time difference between each data when sweeping voltage using keithley 2400

Hello friends,
I am using the sweep vi from Keithley in the SWEEP and Acquire measurement vi.I want to measure the voltage for every step and insert a delay in between every two data, so I need some delay between each I step.
I am a starter to use Labview, thanks so much for your answers.
Perry
Solved!
Go to Solution.
Attachments:
Keithley 24XX Sweep and Acquire Measurements.vi ‏26 KB

As Dennis said, if you're using the built-in sweep function, you'll have to check the manual. See Section 10-16 (That's section 10 page 16, not sections 10 though 16) of the Keithley 2400 User Manual.
The Keithley 24xx series has a measurement speed in units called PLC (Power Line Cycles). The default speed is 1PLC, meaning a measurement is taken every 1 power line cycle, or 1/60th of a second (16.67ms). 24XX's can go from 0.01 PLC (every 0.16ms) to 10 PLC (every 166.6ms). The faster you measure, the lower precision you get.
To set this value programmatically, the command is
ENSe:CURRent:NPLCycles <n>
ENSe:VOLTage:NPLCycles <n>
depending on what you're sensing and where <n> is the number of PLCs from 0.01 to 10.
Another factor that will determine the time between data points is the SDM cycle. These are more complicated, look at your Keithley user manual for more information. Look at Section 6 and Section 11 for more info.
Note:
PLC times are based on a US cycle of 60Hz.

Keithley 2400 Meter Read dans une boucle - probleme de status byte read

Bonjour,
j'utilise un Keithley 2400 pour mesurer un potentiel. J'ai débuté en utilisant le modèle Read.vi du driver. Dans mon cas, la portion "read single" se trouve dans une boucle for et après un certain nombre de mesures (cela semble aléatoire), la fonction gèle et en remontant les étapes, on découvre qu'il s'agit de la lecture de "status byte" qui ne reçoit aucune réponse en amont. Il faut alors redémarrer complètement le programme. Celà survient à chaque fois et après un nombre d'itérations variable.
J'ai même tenté de mettre une boucle while directement dans l'exemple "read single" (le .vi) et le problème est exactement le même, même si on ajoute un wait à la boucle. Après un certain temps, ça gèle et c'est le status read qui ne reçoit aucune réponse.
Merci.

Bonsoir PG123,
Ce que je vois directement dans votre VI c'est le fait que vous exécutiez à la vitesse maximum votre boucle While sans le moindre cadencement ne laissant ainsi jamais de temps disponible au processeur pour effectuer d'autres tâches. Il est propable de plus que l'instrument ne supporte pas un nombre de requêtes aussi élevée saturant peut être son buffer ou ne laissant pas le temps à l'instrument d'écrire correctement les valeurs.
De plus, je pense que vous n'avez pas besoin de récupérer à la vitesse maximum toutes les valeurs possibles provenant de votre instrument. C'est pourquoi je pense qu'une lecture toutes les 200ms suffirait déjà amplement.
Voici donc à quoi devrait ressembler l'intérieur de votre boucle While :
Essayez avec un cadencement d'1 seconde (1000ms en entrée de la fonction) dans un premier temps et voyez si le problème de gel se produit. Si ce n'est pas le cas, vous pourrez alors progressivement diminuer la valeur de cadencement (jusqu'à 200ms minimum, celà devrait suffire comme déjà dit au dessus.
Cordialement,
Jérémy C.
National Instruments France
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Voltage sweep and measure current for Keithley 2400

Dear All
Hello,
anybody can help me?
In spite of nearlly10 days i am searchig to find any labview 2010 program for voltage sweep and measure current that works with RS-232, i has not able finde anything exept some exapmle that read single and multiple data. I has tried to learm labview and changed some prorgram from gpib to RS-232 but i couldn't.
In another attempt i find a good "votltage sweep and measure current" VI that work with RS-232 in labview 5.1.1. i converted it to 2008 but it need to old driver (ke24xx.dll) and dont work in my labview 2010 and I could't find old driver.
in these 10 days, my project on thesis has been stopped and i couldn't do anything for our keithley.
Please helpe...
in following i attached these files:
1-first it is voltage sweep that works with GPIB
2-Vi that i change gpib port to visa (rs232) that i don't know why it dosen't work.
3-it is Vi related to "votltage sweep and measure current" that works with RS-232 but need to old dirver so i can not use it.
4-SubVi needed to run program of 3 (but there is no driver for these subVIs) has been atached in reply post of this post
if any body has this program ("votltage sweep and measure current" that work rs-232) please send for me
thanks in advances.
Solved!
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Attachments:
24xx Swp-V Meas-I gpib.llb ‏373 KB
modifi- arash-24xx Swp-V Meas-I - VISA oNLY.llb ‏172 KB
I V new2.vi ‏103 KB

The first time you asked this exact same question, you were given the way to get the driver and told that one of the examples does exactly what you want to do. You have chosen to disreregard this and pursue other options for these close to 10 days. If your thesis is stalled, that is really your own fault for not listening to the answers you were given. I have no idea why you would do this but I would suggest you go back to the original thread, reread it. and if you want further help, explain what the problem with the NI driver is.

Keithley 2400 voltage Issue

Hello, I am using Labview 2010 to try to control a Keithley 2400 Sourcemeter by GPIB. I am using the labview drivers from the Keithley 24XX drivers package which I downloaded from the "Find Instrument Drivers" in Labview.
I am trying to use the device as a current source to power an electromagnet. I have the device set up and it will output current, but no matter how high I adjust the compliance value, the voltage output of the sourcemeter will not exceed 2 volts.
I'm pretty sure this is not a device limitation because when I adjust the compliance and current manually the device has no trouble. For some reason when I control the device with labview it just won't go over 2 volts. Any help would be great.
I have included my program here. If anyone needs screenshots to diagnose this issue, let me know.
Solved!
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Attachments:
KeTest.vi ‏16 KB

Yep, the "Compl" light is blinking, so it is the range compliance. The range compliance is set at 2.1V. I added the "Configure Measurement" vi and set the vi to Auto, but this didn't change the range compliance.
Also, I set the Auto to false and tried adjusting the "Manual Range." When I get above 2.1 V, I get a message that says :
Instrument reports:
824,"Cannot exceed compliance range"
I have included the latest VI here
Is there a VI that changes the compliance range, or a VI that sets it to auto?
Attachments:
KeTest.vi ‏18 KB

Keithley 2400 and 2182 V-I measurements

Can anyone help me with a program in Labview regarding V-I measurements with a Keithley 2400 source meter and 2182 nanovoltmeter?
Thanks!

Hi danimarconi,
"anyone" will help you as soon as you ask specific questions!
Tell us your problems, attach your VIs and you will get help!
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome

Keithley 2400 VISA driver limited resolution

Hi,
I have a Keithley 2400 sourcemeter, what I use in the +-1mA range, as a current-source. This is the driving part of a PID control.
I use the official VISA drivers, and everything is okey, except that, it seems I cannot use the specified resolution from LabView.
In this low +-1 milliAmp range, the usable resolution is 50 nanoAmperes. In manual mode, everything is ok, I can set for example an output current to be:
-0.245450 mAmperes.
But when I use LabView with the Configure Output .vi from the official llvlib package (i attached it) it rounds for microAmps:
For example the above double value will become: -0.245 mAmperes.
This is really bad for my project, since I need the 50 nanoAmp resolution for the really fine control.
Can someone help me?
Thanks in advance!
Solved!
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Attachments:
Configure Output.vi ‏18 KB

Thanks very much!
Now I learnt that, I should be always suspicious even with "official" libraries and drivers.
Actually there are two LabView drivers for Keithley 2400, one from Keithley, it is an exe installer type, and the other from National Instruments. I became curious about this bug, and I checked the Keithley VISA drivers, they are okey, they use everywhere double precision variables.
But if you have a look at the NI Keithley 24XX.lvlib:VI Tree.vi, where is the full list for available VIs, there are many problems I think. At many places (voltage sensing, sourcing, etc) the programmer just used single precision variables to pass information.
I think these problems should be reported toward NI, but I do not know what is the way to do this...

Error using the Keithley 2400

Hi, I am pretty new to LabVIEW and right now I am just trying to set up a simple test (source current, measure voltage) using the Keithley 2400 and Labview 8.2
I got the driver for this instrument off of NI's website at
http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=25B255F3AA83660EE0440003BA7CCD...
In the Measurement and Automator it sees the Keithley (GPIB0::14::INSTR) and I also gave it an alias so it is easier to find amungst the other hardware current set up.
I wrote a simple program using some of the VIs in the driver to source a current and read a voltage. When the program runs, it errors out, and then after it errors the keithley still runs the test. I can see the measurement on the front panel of the instrument however it does not send anything back to the computer.
I then tried to just run an example found in the driver and I get the exact same error.
Error -1074000000 occurred at Keithley 24XX.lvlib:Error Query.vi
Possible reason(s):
Instrument reports:
-113,"Undefined header"
0,"No error"
Complete call chain:
     Keithley 24XX.lvlib:Error Query.vi
     Keithley 24XX.lvlib:Read (Multiple Points).vi
     Keithley 24XX.lvlib:Read (Single Point).vi
     Keithley 24XX Read Single.vi
Anyone have any idea's as to what might be causing this error? Any help would be greatly appreciated
Nolan

Hello nblue:
Can you communicate with the Keithley 2400 in Measurement and Automation? Do you know if there is a query command for the instrument, if so can you test to see if you can query the instrument to make sure it is working.
Regards,
Roland A.
Applications Engineer
National Instruments
Check out VI Roadshow

"Read Single Point" Keithley 2400 Problems

Hello!
I am recentely having some problems with the "Read Single Point Measurements" function in Labview 2012. I have already sucessfully used my Keithley 2400 in other programs to sweep the voltage, but now I am trying to use it also to read the current across my sample.
I wrote a very simple program, which resemble the one you can find among Labview examples (see 1st attachment). The only differences are a sweep-subVI and a "for" cycle. My problem occurs at the "Read" Keithley function. On the Keithley's screen I have the following errors:
- 113 : undefined header;
- 230: data corrupt or stale;
- 420: query unterminated.
While in the Block diagram, when the system gets to the "read" function, the error -1074000000 shows up.
I have found a lot of posts on this topic, but unfortunately I could not find the any solution for me. I also tried the 2nd attached program, to check the comunication to the instrument, but errors still occur. In "Measurements and Automatic", it says that the instrument is working properly.
Do you have any ideas?
Thanks
Attachments:
Keithley 24XX Sweep and Acquire Measurements.vi ‏26 KB
Basic Serial Write and Read (1).vi ‏26 KB

The following video demonstrates how to check the firmware revision: http://www.keithley.nl/centralized_display?mn=2400&assetid=55934.
In order to update the firmware you will be need to download a flash program and the firmware file. gAfter obtaining the Flash program and the Firmware file from Keithley Application support staff, unzip the three files in a folder of your choice and run the "setup.exe" program. Follow the instructions to install the program. When the installation is complete, launch the program from your Windows Start menu under Programs/Keithley Instruments. The Application support staff will also provide the file for the latest firmware revision. Put that file in a folder where you can find it and then run the Flash Wizard32 program. The program will autodetect the instrument and request to specify the firmware file.
This link contains the flash program: http://www.keithley.com/base_download?dassetid=52609
See attactment for the firmware revision.
Attachments:
2400c30.zip ‏358 KB

Keithley 2400 Trigger 2000

Hi,
I have tried for a couple of days to let a Keithley 2400 source current and measure voltage and at the same time trigger a DMM2000 on which a current will be measured. This is for use in a LIV characterization. I�m using Labview but prefer to write directly to the bus instead of using the Labview drivers, which I find a bit complicated to use.
First I configure the 2400 with the following commands
*RST;
TRAC:CLE;
SOUR:FUNC:MODE CURR;
SOURWEPAC LIN;
SOUR:CURRTAR 0;
SOUR:CURRTOP 0.1;
SOUR:CURRTEP 0.0001;
TRIG:COUN 100;
SOUR:CURR:MODE SWE;
SENS:FUNC "VOLT";
FORM:ELEM CURR,VOLT;
TRIGOUR TLINK;
TRIG:INP SOUR;
TRIGUTP SENS;
Then I write the following to the DMM 2000 to initialize
*RST;
TRAC:CLE;
SE
NS:FUNC "CURR";
TRIGOUR EXT;
TRIG:COUN 100;
Now the two instruments should trigger each other.
I then write to the 2400 to turn on and initiate the sweep.
OUTP ON;
INIT;
And finally an INIT is sent to the DMM2000 to initiate this instrument
This starts the measurement ONLY if the instruments have been turned on just before the program is executed.
If I run the full program again it doesn�t start. What is wrong?
If I run the program from the initialization of the 2000 it works well. But if the intialization of the 2400 is included it just wont start the sweep.
Any suggestions?
Regards
Francis

You may wish to try this. I struggled with a 2400 for some time. After a single reading, the buffer in the 2400 contains current, voltage, ohms, a timestamp and another variable. You have to read the entire buffer of the 2400 or it ignors future commands. I struggled with the 2400 drivers also. The help files of the drivers did not describe one of the variable inputs. Finally, I figured out that it was leaving data in the buffer. I increased the variable to read all five values and it finally worked!
You will have a different solution because you are not using the drivers. But I suspect you may have the same problem. You will have to write commands to be certain you extract all measurment information for the reading. Perhaps the DMM may also have a simi
lar feature. If you do not read all the data, the systems will hang.

IV characteristic using Keithley 2400, Labview IVI driver

Hi...
I'm Pradeep. I am trying to build a LV program for measuring LjV (luminance-current density-voltage) Characteristic of LED using while loop. I am in the first part of building a program for IV characteristic. I am using Keithley 2400 (connected through PCI-GPIB) for sourcing Voltage and measure Current through the device. I use IVI driver from Keithley website (2400-854B01) in Labview 2010.
I have made a program (please find it in attachments), while running it shows an error code -110. I fear that the voltage that I want to send to 2400 is not communicated properly. Can someone please help in finding out where I made a mistake. I'm struck for two days. I have used Initialize, Configure SOurce DC, Enable Source, Configure Measurement, GPIB Write, Read and Close from the driver (though not sure of the order to be used)
Please ignore the Luminance measurement in the LV program at 'XY graph' and at 'Write to Spreadsheet' which are for later use when I need to add a photodiode with Keithley 2000 DMM.
(I did not do a structured learning of Labview. I have been learning from manuals and through discussion forums for a couple of weeks. Please pardon my ignorance)
Attachments:
LjV char.vi ‏22 KB

duplicate

How can I measure above 100 point by Keithley 2400?

Hello!
I am using Keithley 2400 and Labview 6.0. I have some questions.
1) In my program, I cannot measure above 100 points. The limit that I can measure is only 100 points. In order to measure 1000 point, what should I do?
2) I want to make "Sweep Voltage" by Step Voltage [start:0V, stop: 5V, step: 0.1V. I have already implemented this, but my program is not good. Could you modify my progrma?
Thank you!

I don't have 6.0 installed anymore - I hope this image helps.
Attachments:
answer.gif ‏132 KB

Cannot communicate to Keithley 2400

I wrote a small Vi for using Keithley 2400 to measure Voltage based on labview 6.2. After 10 month, I found that my program cannot talk to the Keithley 2400. I do not know becasue I upgrade Labview to labview 8.2, or someone deleted some key drivers for GPIB in this public computer. I attached the Vi. Thanks so much for help.
Attachments:
volttest2.vi ‏81 KB

See the red border around the whole edge of your block diagram? That's the breakpoint that's sorrounding your entire block diagram. Breakpoints are shown by either big red circles if they're on a wire, or a red border around a VI/function if it's set on a VI/function. In this case you must have accidentally clicked on the block diagram.
Have you taken any of the LabVIEW tutorials? To learn more about LabVIEW it is recommended that you go through the introduction material, tutorial(s), and other material in the NI Developer Zone's Learning Center which provides links to other materials and other tutorials. You can also take the online courses for free.

Will USB-6008 DAQ be able to power and record voltage for UMS T5 tensiometer at the same time?

I would like to use my NI USB-6008 to provide power to my UMS T5 tensiometer (http://www.ums-muc.de/en/products/tensiometer/t5.html) as well as take readings from it, but I don't know if this is possible to do properly. The supply voltage for the instrument can be as low as 5V, which I can easily get from the dedicated +5V channel. I am able to power the instrument and connect it to an analog input on the 6008 and measure a voltage in differential mode. However, while reading the support literature for the instrument, I find the following:
"Potential data acquisition pitfalls: Because the pressure transducer is configured in a Wheatstone full bridge, the input voltage and signal mV output cannot be connected to the same reference (ground). Hence, the signal mV output can only be measured using a differential voltage measurement. Therefore, do not attempt to make a single-ended measurement of the pressure transducer mV output." (http://www.decagon.com/assets/Uploads/MeasuringUMSTensiometerswithnon-UMSControlandDataAcquisitionSystems.pdf)
My understanding is that the 6008 can take a differential measurement if I attach the signal "+" and signal "-" to the positive and negative analog input terminals. However, it seems that all of the Ground ports on the 6008 are grounded to the same reference, which would make my voltage measurement invalid according to the paragraph above. So my real questions is: if I attempt to record the voltage using one of the analog inputs on the 6008 in this way, is the measurement valid? Or do I need to find a separate power supply with a different reference ground to ensure that the measurement is accurate?

The specification sheet for that device is very poor. The manual is not much better. Companies which want to sell scientific equipment should publish decent data sheets or get out of business.
In section 3.4.3 General requirements the device is described as a "non-amplified bridge circuit." This information along with the bridge impedance should be in the specifications because it is essential to applying the device under any circumstances other than the nominal behavior at 10.6 V.
The answer to your question is this:
You can use it with the USB-6008. The 5 V power supply will result in output voltages slightly less than half (5/10.6) the voltages specified under nominal conditions. You can use the differential input mode on the USB-6008. The absolute input voltages will be about 2.5 V with the 5 V supply. That voltage is within the working range of the device. The differences will probably be less than 100 mV. The resolution of the USB-6008 on the +/-1 V range is about 0.5 mV so your pressure resolution will be around 1 % of full scale. The input impedance and termination voltage of the USB-6008 will introduce some errors. These may be on the order of 5-10%. I cannot predict much better without the missing bridge impedance specification. Those errors should be systematic and relatively constant. A calibration of the whole system - sensor and DAQ device together should allow you to compensate for much of that error.
Lynn

Swap DC and ground voltages of Keithley 2400 meter

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