Pxi-4071 constant current

We use 4110 voltage source for current measurements on pxi-4071. We supply high-ohm (1.5 GigaOhm) resistor with few volts and measure current on 4071. All cables are shielded on ground of 4110 voltage source, but cables are about 5 meters long. What can be reason for constant current 5 nA at zero supply voltage? We don't know whether it software or hardware problem, and i already asked this question in LabView forum, autozero enabled in max doesn't help. Could be a reason bad shielding of ground in pxi-4110 voltage source

I would focus on the hardware side initially. I would try the following steps.
1) Make a current measurement on the 4071 with the inputs open to see if there is an offset. If so we should look into the DMM configuration.
2) Connect your cabling and/or resistor without the 4110. If this adds the offset then it seems to be shielding/noise related.
3) Connect the cabling and/or resistor to the 4110 with the output disabled. If this adds the offset then it could be ground related or also related to an offset in the 4110 output.
Steve B

Similar Messages

Pxi-4071 shielding cable

Hi, we use pxi-4071 on pxi-1033 for measurments and we connected shielded cables few meters long. We wrapped foil cables from the kit. After that we connected all the shields to the ground from the power supply. But we still remain interferences about 1nA and DC component 5nA. If anyone faced a similar problem, is it possible that we are too often measured current. Can you advise the shilded cables for multimeter in this case.

alyast wrote:
Yes, we pretty sure in shielding, but we don't know why there is current constant component (5nA), while declared sensitivity - 0.1nA. Probably some bug with timing in LabView or something? I don't know what could be a reason for this behavior, and therefore ask noob questions.
Why would you suspect the software when all the evidence points to an issue with the HARDWARE? And if you're measuring in the nanoAmp region, you'd better be ABSOLUTLEY certain that your grounds are true and accurate. Probably grounding to your power supply is not good enough. Your power supply probably has to be grounded to a copper stake going - what is, it, six feet? - into the ground.
Bill
(Mid-Level minion.)
My support system ensures that I don't look totally incompetent.
Proud to say that I've progressed beyond knowing just enough to be dangerous. I now know enough to know that I have no clue about anything at all.

How to acquire data through multiple channels in parallel using PXI 6070 E, PXI 4071 and LabVIEW?

Hi,
I am using NI LabVIEW, NI PXI 4071, and NI PXI 6070E to measure current through a variable resistance. Now, I am using one channel from SCB-68, but I want to add another channel in parallel so that I can have two resistors instead of one that I cam measure current through them.
I have attached a Pdf file showing the setup for hardware in use and LabVIEW code also.
Can anyone look at these files and give me guide lines or ideas that can help me resolving this issue, please.
Thanks in advance.
Best Regards,
Shaheen.
Solved!
Go to Solution.
Attachments:
IV copy for HS.vi ‏55 KB
Layout of NI Cards.pdf ‏248 KB

Your 4071 can only do one measurement at a time. Your DAQ cannot measure resistance either nor has it got any analogue inputs.
However, you could use a multiplexer and multiplex your 4071 DMM. This wont give you simultaneous measurements but can acquire data one after the other, the speed is obviously dependent on the multiplexer you choose!
Hope this helps.
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Measure Power using Labview and two PXI-4071 DMMs

Hello,
I am trying to make a simple VI. I am measuring input AC voltage and Current using two PXI-4071 DMMs. I want to Calculate Power and Power Factor. I am able to read the voltage and current fine. I just dont know how to calculate the power and power factor. Im looking for real power not watt*amps. Please Help.
Scott
Attached is my VI
Attachments:
Measure AC Voltage and Current.vi ‏42 KB

Scott,
It appears that another applications engineer (Sean_N) has been assigned your initial forum post. I assure you that he is working on finding an answer to your question. We would like for our customers to limit questions to one forum so that we do not duplicate efforts on our end. I will contact Sean to remind him that you are awaiting a response. I will also point all future traffic from this post to your initial one.
Thanks,
Kareem W.
National Instruments
Web Product Manager

Pxi-4071 ranges

Why is it so hard to find the ranges for the PXI-4071??????? I called National and they told me:
The ranges that are possible to use are:
+-.02
+-.20
+-2
+-25
+-250
Yet when I open the soft front panel there is a range up to 1000 volts. Where is this listed?? I need ranges for VDC, current dc and resistance ( opens...infinite) I'm using the DMM drivers that ships w LV 8.6.
Thanks

All of the range specifications will be found in the PXI-4071 user guide and specifications document.
If you search on ni.com for 4071 you will find the PXI-4071 product page. Going to the specifications tab, and then clicking "detailed specifications" opens this document. It contains all of the specifications and accuracy ratings of the device.
NI 4071 Specifications (Multilingual)
Page two specifies that for DC voltage the following are valid ranges:
100mV
1V
10V
100V
1000V
which also show up in the DMM soft front panel.
For DC current, see page 4, which states
1uA
10uA
100uA
1mA
10mA
100mA
1A
3A
Resistance, page 5,
100Ohm
1kOhm
10k
100k
1M
10M
30M
100M
5G
Thse pages also have the charts for the accuracy of the DMM at each one of these ratings.
Eric S.
AE Specialist | Global Support
National Instruments

Pxi-4071 error on calibration executive

hi!
i have this little problem with my NI calibration executive. The error says
" Error-1071001424 occurred at Error-1071001424 occurred at ***configcalibratorandwait.vi
Possible reason(s)
Current Compliant Voltage Exceeded".
Can you guys help me on this? I am calibrating this NI DMM PXI-4071. Please see attached captured error.
thanks.
ating

popoi,
Thanks for posting on the NI forums. I have a couple questions for you that should help us get to the bottom of the problem.
What version of Calibration Executive are you using? You should be able to find this by going to the Help Menu >> About Calibration Executive.
What Equipment are you using to perform the calibration? There is a list of equipment here.
Is this the only board that you are having difficulty calibrating with Calibration Executive?
Thanks!
Aaron W.
National Instruments
CLA, CTA and CPI

Setting up the sample rate on a PXI-4071

I am new to this and hoping that some one can help...
I have a DC power supply connected to a PXI-4071 that I am attempting to get some stable DC voltage measurements using LabView but
the measeurement values are all over the board so I am guessing that I am missing some sort of sample rate set up.
Any suggestions?
Thanks
Attachments:
My VoltageRead.vi ‏30 KB

I figured it out..
I had my constant "2" wired to the function instead of the resolution...

Setting Input Resistance on the PXI-4071

The specifications for the PXI-4071 DMM indicate that the input resistance can be chosen as either 10 MOhm or 10 GOhm for the 100 mV, 1 V, and 10 V ranges. I see where this can be input on the instrument soft panel, but I have been unable to locate how to configure the input resistance when using the DMM in a VI. Suggestions?
Thanks!
Jeff
Jeffrey Zola
Solved!
Go to Solution.

You need to use a property node.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
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Attachments:
input resistance.png ‏13 KB

Pxi-4071 aux I/O how to output a control signal?

HI, I am working on Pxi-4071 dmm card. I want to use aux I/O to out put a control signal for a relay on/off. Technically, I want to know how to do it with labview. Is any examples to start?
Thanks
Liming

Hello Liming,
The DMM is capable of sending TTL triggers out on both the PXI_Trig lines and on the AUX connector on the front connection. These signals are intended for controlling National Instruments switch modules and not powering/closing third party relays.
If you're looking to control a National Instruments Switch there are example programs that demonstrate synchronous scanning with DMMs and Switches. To locate these examples open LabVIEW and go to Help» Find Exampled... Then Navigate to Hardware Input and Output» Modular Instruments» NI-Switch (Switches).
If this isn't what you're looking to do, or if you have additional questions, please feel free to post back with more information.
Have a great weekend!
Brooks

Error -1074118625 with PXI-4071 and PXI-2527

When using the LabVIEW IVI drivers for PXI-4071 and PXI-2527, I receive an error -1074118625 in TestStand. The sequence initializes the MUX, init DMM, connects the MUX, waits for debounce, and then upon reading from the DMM, I receive this error.
Error: niDMM Read Waveform (waveform data).viExplanation could not be found for the requested status code.
Verify that the requested status code is correct.
[Error Code: -1074118625, User-defined error code.]
This sequence of events is successfully used multiple times elsewhere in the TestStand. This error does not appear in any knowledgebase article nor in any help. Any explanation would be greatly appreciated.
Solved!
Go to Solution.

I found this with google that seems like it might apply:
http://digital.ni.com/public.nsf/allkb/A593DEBFD86A69C68625727900748EEC

Constant current excitation for strain gauges

Ideally I would like to log 46 strain gauges using a scxi-1000. At the moment we have two 1102B modules, one 1100 module, and a 1122 module.
The 1122 module supports quarter bridge strain gauges but is very limited in scan rates when logging 16 strain gauges all at once.
Stuart from ni gave me an idea of constant current excitation for the strain gauges. The 1581 would be very suitable seem it delivers 32 channels of costant current and would suit the 32 channels of the 1102B we already have. Only problem is whether the 100 micro amps will be sufficient current to excite the strain gauges with reasonable accuracy.
The remaining strain gauges that wouldn't fit into the 1581 would run on a 6 channel strain gauge amplifier and then run through the other 1102 module we have and use a datataker for any left overs.
Any other suggestions? I have looked into buying either the 1521B for 24 channel quarter bridge or two 1520's but am unable to purchase these at the current time.
Thanks for your time.
Message Edited by Peter W Brown on 01-11-2006 09:55 PM

The full range of a strain gage in most applications is going to be
less than 1 ohm, which means that a typically strain application needs
to be able to measure the output on the order of fractions of an ohm to
be even remotely close to accurate.
The reason strain gages are typically put in a bridge configuration is
so that their output can be centered around 0V which enables the signal
conditioning module to apply very large amounts of gain to the
measurement (up to 2000 on the SCXI-1520). Without this gain, the
sensitivity of the strain gage is so small that you will be very
hard-pressed to get remotely accurate readings.
For this reason alone, I don't think there is a current-excitation
solution available that will enable you to get sufficient resolution
from the strain gage reading.
The SCXI-1521 is probably your best solution for measuring a large
number of quarter bridge strain gages. If you also need to measure
other bridge configurations (i.e. half or full) then the SCXI-1520 is
your other option.
-Logan K

Why would a PXI 4071 measuring resistance countinue to increase the measured valued for each measurement?

I have a PXI-4071 DMM and I am measuring a connection in the UUT. The value should be around 0.3 ohms. The program (exe) will run aprox. 20 times and during these 20 runs the measured value will progressively increase until is is over the limit of 1.5 ohms. If I shut down the exe and run the VI as a standalone (continuous loop), the resistance will gradually come down to 0.3 ohms. I then close LabView and restart my exe and the readings are normal (0.3) but then continue to increase until they are over 1.5 ohms. This process has been repeatable for the last week. I have attached the code I am running. What could be the problem with the DMM code?
Attachments:
DMM_MeasResistance2.vi ‏64 KB

Uninitialized shift registers are a good thing to check for such a problem. Do you see the same response with a soft panel and your DMM? if not then it is in code. Uninitialized shift registers would start at 0 (default is usually 0) and will retain their values from run to run. Just a possibility dont have LV up right now so I cant check the code sorry,
Paul
Paul Falkenstein
Coleman Technologies Inc.
CLA, CPI, AIA-Vision
Labview 4.0- 2013, RT, Vision, FPGA

Constant current source from USB-6212 (bus powered)

Does anyone have any quick and dirty tricks to get a reasonable constant current out from this device...say in the range of 4-20mA? Accuracy requirement is low.

The 6212 only supports voltage outputs.
You could try converters such as these, just an example of one of many manufacturers.
Some modules are bandwidth limited, so be sure to check the specs if you need to make changes in current quickly.
http://www.dataforth.com/functional.view.aspx?ptypeid=9
-AK2DM
~~~~~~~~~~~~~~~~~~~~~~~~~~
"It’s the questions that drive us.”
~~~~~~~~~~~~~~~~~~~~~~~~~~

LV12 How to configure PXI-4070 DMM current function?

Dear all
I have a problem about LV12 software to config PXI-4070 DMM current function.
my vi...NI DMM initial >>>NI DMM reset >>> NI DMM Configure Measurement (Current function) >>> NI DMM Reading >>>>
When I testing with my vi, the calibrator (source) error "Current Compliance Voltage Exceeded".
but when I testing with DMM front panel 3.0, the calibrator can generated current and PXI-4070 can reading.
Please help me to solve this problem.
Regard,
Sermsak.
Solved!
Go to Solution.

The error looks like it is related to a power supply or an SMU that is trying to source something out of its specified range.
Info about compliance:
http://zone.ni.com/reference/en-XX/help/370736L-01/ni_dc_power_supplies_help/compliance/
http://zone.ni.com/reference/en-XX/help/370736L-01/nidcpowerviref/nidcpower_query_in_compliance/
Things to consider:
1) Where in the code is the error occurring?
2) Can you run example NI-DMM code? (from Help>>find examples>>Hardware I/O>>Modular Instruments>>NI-DMM)

PXI 4071 error

你好：
我有一张PXI-4071的DMM ,用MAX的NI-DMM SOFT FRONT PANEL程序时，显示OVLD V DC,正常的都是.显示数值0.00000000 V DC，请问这是什么引起的？是这张卡坏了吗？

DMM线都没接，没有量测动作的时情况下，打开程序就直接OVLD,如下图所示
附件:
PXI DMM-4071.PNG ‏73 KB

Pxi-4071 constant current

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