Signal cross talk on pci 6014?

I am using a pci 6014 with a scc 68 wiring box two acquire two analog signals.
In AI 12, there is a amplified strain guage signal which spans 0-10v.
In AI 5, there is am amplified DC LVDT signal which spans -5 to +5V.
A respective ground from each sensor goes to the scc break out box.
When a sinusoidal signal is applied to the load cell, some of that signal is seen on the LVDT channel.
Yet, the LVDT has the core removed and is a large distance away from the project.
This strain guage signal shows up around 2V peak to peak on the lvdt channel.
Yet, if I stimulate the LVDT, I can see the signal clearly in both labview and on an oscilloscope.
None of the LVDT signal is seen on the load cell.
If i place an oscillosope on the LVDT output signal, the signal appears clean down to 20m regardless of strain guage stimulation.
It is only when plotting/charting in labview that Im seeing the strain signal on the lvdt channel.
Ill attach an example file from ni which is modified to read two channels at the same time, and the problem can be seen with this file.
I doublt the programming is the is the problem though.
Message Edited by jimmyinct3 on 11-13-2009 03:19 PM
Attachments:
Acq&Graph Voltage-Int Clk.vi ‏21 KB

Have you terminated non-connected signals with a 50 Ohm resistor?
I am not familiar with the 6014, but it might be an ADC with one converter, adding a terminated channel in between two channels might be a good idea if so.
Ton
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Similar Messages

How can I convert a 0-50mA signal to 0-5 VDC for use by a PCI-6014 DAQ?

I have a PCI-6014 DAQ card. I am trying to measure the output of a closed-loop current sensor, which has an output of 0-50mA. When I tried using a 100 ohm resistor as a load (to measure across the resistor to get a voltage input for the DAQ) I get an AC voltage reading! I do not know how to convert the AC Voltage to a varying DC voltage. Most AC-DC converters output a fixed DC voltage (3.3V, 12V, 15V, etc.). Can the PCI-6014 measure the current directly OR is there a method to measure the VARYING 0-5 volt AC voltage? Please be specific, if possible. Thanks in advance!

Hello,
PCI-6014 can measure an AC voltage directly. The Test Panels in MAX will show the peak voltage level of a signal, and not the root mean square (RMS) voltage. For example, if you measure the 120 VAC 60 Hz sinusoidal waveform that is available from a standard North American wall outlet, you will see a wave with a peak of about 170 V.
The conversion between VRMS and Vo is VRMS = Vo/√2.
You will need to determine whether you expect your AC signal to be in units RMS or peak-voltage and make the conversion, if necessary, using the formula above.
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Maximum input frequency of the PCI-6014?

I am using the PCI-6014 configured for digital inputs. At low frequencies my quantized waveform is very smooth however wheni increase my input frequency, teh waveform becomes highly distorted. Im sure its not my A/D converter becomes i am sampling more that eight times the input frequency. Can you please help me!

Hi St Augustine,
This issue could occur if you are sampling on 2 or more channels. If this is the case, you are probably seeing cross-talk (channel ghosting) where voltages on previous channels are being seen on subsequent channels in your sample list. For example, if you have a sinewave on the first channel and 5V on the second channel, you might see remnants of each channel on the other, distorting your signal slightly. The best way to correct this is to increase the interchannel delay.
Data Acquisition: Troubleshooting Unexpected Voltages or Cross-talk in Analog Input Channels
http://digital.ni.com/public.nsf/websearch/B9BCDFD960C06B9186256A37007490CD?OpenDocument
If you are only sampling on one channel, you could check in Measurement & Automa
tion Explorer (MAX) to make sure that you are seeing the same phenomenon being exhibited by the waveform. In MAX, you can right-click your PCI-6014 device and select Test Panels. Then you can adjust the sampling rate and watch the waveform directly from the front end of the driver.
Another point is that it could still be that you are seeing granularity because of the high frequency of your signal relative to your sampling rate. A sampling rate of 8x higher will still look much more "squarish" then a sampling rate 100x faster.
Anyway, hope that helps. Have a good day.
Ron

Cross talk in BNC 2090

Thanks for the information provided. I followed your advice by connecting
DGND1 with a wire to USER1 and DGND2 to USER2. But I still get cross talk.
It also puzzles with a fact that when I connect a signal source (from a
functional generator) to ACH1 but in fact the signals show up on the
Biobench screen as ACH0 as defined. So my hunch is that something wrong
happens to BNC 2090 or the PCI-MIO-16XE-50 board installed in the computer.
Would it be possible for me to send in the BNC2090 for a check? If so, what
are the procedures to follow.

We handle all repair requests over the phone. The procedure is as follows:
1. Go to www.ni.com/ask to create your own Service Request number (SR#). Choose the Phone NI option. Fill in the form with the appropriate information.
2. Call the support number that is given to you and enter in your SR#. You will be directed to an Applications Engineer (AE) that will assist you through the process. The AE will be able to answer any questions you may have about the repair process.
Have a great day.

Eeprom address and caldacs model/address for pci-6014 and pci-6733

I have one pci-6014 and one pci-6733.
I need to transfer the calibration constants from eeprom to caldacs.
I search the adrress of the constants in the eeprom and the model and address of che caldacs.
Tanks

Hello,
It seems to be a common mode voltage or ground loop problem.
When you are sourcing an output signal from your DAQ board, the signal is already grounded, it means that it has already a reference. If you measure this output with a measurement device, which has also a ground, the both ground potential are not necessary equal. This difference is the common mode voltage and influences your measurement (offset).
Please check the following links to have more detail about grounded signal.
http://zone.ni.com/devzone/conceptd.nsf/webmain/8D907374C5E867F186256C640059F30C?opendocument
http://digital.ni.com/worldwide/france.nsf/webtechsupp/0E6A8D5999CEE1AF8025683C0056A4B1?OpenDocument&node=163080_f
Best regards,
Alexandre D
National Instruments

Wrong duty cycle (pci 6014 and bnc2110)

Hello,
I want to generate a square signal with labview 7.0, pci 6014 and bnc 2110. I attached my VI . The duty cycle works properly for instance for 10%, 20%, 30% (I suppose that it works because when I anlyse the signal: some pulse seams to not appear ) . BUT when I change the duty cycle constant to 15%: the output is again 20% and not 15%. It's the same case for 17%, 18%....
I really need to create square signal with a perfect duty cycle.
Do you know where is the problem?
Thank you
labview 7.0
Attachments:
Untitled41.vi ‏310 KB

I found the problem for missing pulse: it's the while loop. I delete it and add more samples.
The duty cycle works now due to the precision of the "simulate signal"
labview 7.0

RE: local variable cross-talk?

Jeff
A global can be considered as a variable to the entire code, where lots of
different vi's can operate it. Locals only have any meaning within their
own vi, or instances of their own vi.
If anything writes to a particular global, whether in reenterent vi's or
not, it's available everywhere in the code.
What you were asking was about locals though. If a vi is non-renentrant
(i.e. as they come out of the box) then the values in the locals are vi
specific, no matter where the vi is, where it was last used, it retains the
data from it's last operation. If it is re-entrant, then the values in the
locals for each occurance of the vi are its own for EACH instance, i.e. just
like different locals in different vi's, it doesn't matter where else the vi
is used, the data held is that from the last operation of that specific
instance.
Simple way to demonstrate this. Make a vi that has one numeric control,
then code in +1 and get it to write to a local variable for that control.
Throw in an indicator to wire out the result of what is written to the local
for the control.
Then take this vi, put it in a for loop, then put another copy in the for
loop as well. Wire the indicators to the side of the for loop and create
indicator arrays for them. Get the loop to run 6 times say. Now try
running this with the vi in the for loop non-reentrant and then reenterrant.
One way the arrays will contain either all the odd no.s 1,3,5,7,9,11 and
then the other array 2,4,6,8,10,12 (don't know which array will be which,
depends which executes first in the for loop of this example). The other
way they will both be 1,2,3,4,5,6. In the first example, the same vi has
run 12 times, i.e. one copy of the vi which retains its info and is called
in many places and therefore only has one set of values, and the other with
two re-enterant copies where they have their information specific to that
instance of them i.e. effectively they are different vi's. Both ways are
useful, depends what you want.
If you're looking for a use for non-reenterant vi's then consider this:-
For instance. Supposing you get many things to try to write to a global
array of numbers, and you have two vi's one "A" writes to the first element
in the array and the other "B" writes to the second element. Because in LV
you have to read a global first and then write to it to perform a change,
these independant vi's "A" and "B" (be they re-enterant versions of the same
vi, or different vi's), can be performing the tasks simultaneously in the
code. I.e. "A" reads, "B" reads, "A" writes, and "B" writes over the top
with a modified version of what it read, and "A"'s changes are lost. This
is what's known as a "race condition" as "A" hadn't finished and "B" needed
to know what "A" was going to write before "B" performed "A" read. Try it,
hours of fun if you code this kind of thing in inadvertantly!
If the same vi is used, and is not re enterant, it can only run in one
instance at a time, hence two read / write operations cannot be performed
together, problem solved. Unless that gives you timing issues of course,
waiting for one to finish, to write the other......but that's another whole
can of worms.
cheers
Tim Price
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-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of Jeffrey W Percival
Sent: 29 November 2001 21:12
To: [email protected]
Subject: Re: local variable cross-talk?
Another useful reply! What a great news group this is.
One last thing I wanted to ask about, though, is global vs. local. I see
you talk about globals, but in fact the variables in my subVI's were locals.
I can easily understand the behavior I observed accompanying the use of
global variables, But I guess the use of the word "local" stumped me.
Should I interpret "local" in LabVIEW's sense to mean "local to all
instances of this VI"? And global to mean "visible to all instances of this
VI as well as other VI's"?
-Jeff
Tim Price wrote:
This facility is actually very useful, for instances where you want to
encapsulate some code so that it can only run in one place at a time,
i.e.
global arrays that are written to in more than one place. This method
can
eradicate race conditions completely for example when used like this.
There
are multiple other uses as well.
However, using a vi as a module of code, to run in more than one
instance at
a time simultaneously, re-entrant is the way to go. Just make sure you
debug it first!!!
Remember though, just because a vi may be re-eneterant, doesn't mean
that
everything inside is; sub-vi's, Globals etc. The classic one I've seen
is
where people think that a re-enterant vi is talking to it's own copy of
any
Globals used within it, i.e. counters etc., where in actual fact of
course,
they are all using the same Globals.
Worth playing with a few examples to get familiar with it.
Tim Price
Jeffrey W Percival, Senior Scientist and Associate Director
Space Astronomy Laboratory, University of Wisconsin - Madison
1150 University Ave, Madison, WI 53706 USA
608-262-8686 (fax 608-263-0361) [email protected]
http://www.sal.wisc.edu/~jwp

Tim Price wrote:
Tim, thanks very much. I'll try the experiment you suggest.
Thanks for taking the time.
-Jeff
Jeffrey W Percival, Senior Scientist and Associate Director
Space Astronomy Laboratory, University of Wisconsin - Madison
1150 University Ave, Madison, WI 53706 USA
608-262-8686 (fax 608-263-0361) [email protected] http://www.sal.wisc.edu/~jwp

Incremental encoder: reset counter on pci 6014?

I want to connect an incremental encoder with A, B and Z to a PCI 6014 card. I found some VI's for counting A and B (DAQmx->Counter->Count Digital Events; DAQmx->Counter->Measure Posititon) . However I can't figure out what to do with the Z. Is there a way to reset the counters by Z? (I am using labview 2009)
Thank you very much!

Sorry, my fault. I didn't see you have an E-Series device.
Resetting your counter with a digital trigger is possible for Counter/Timer devices but not for your PCI 6014.
You can reset the counter with DAQmx by stopping and starting the task again. You could read your Z index on a digital input, if the input goes high (or low) you could reset the counter.
DAQmx: Count Digital Events with Option to Reset Counter
http://decibel.ni.com/content/docs/DOC-6576
I think this is the only way for the PCI 6014. Since you have to go through several software layers, the performance goes down a bit. If it is possible, i would recommend to change to a M-Series device...
Cheggers
Sascha E.
Group Leader Applications Engineering
National Instruments Switzerland

PCI-6014 not recognized by Windows 2000

I recently purchased and just installed a PCI-6014 in a new Dell Optiplex running Windows 2000 (sp2, we have stayed at sp2 due to problems we have had with sp3, sp4). On this same machine I have LabVIEW 7.0 with all the bells, including NI-DAQ 7.0. When I put the pci card in for the first time (and every one of many times I have restarted since) I NEVER have seen the "new hardware found" message come up. That's bad sign one. And the hardware device manager doesn't see it either (I think that would follow from no new hardware being detected..) Then I have run MAX 3.0 (also on the machine) and all it finds is this bizarre thing called "PXI System" under devices and interfaces. I also have an eight port serial card in this machine which MAX does see. I eventually removed both the Serial card and the PCI-6014 (daq card) and even after a restart the "PXI system" device or whatever STILL shows up under devices and interfaces... So I just don't know what that is?? Any help there would be appreciated.. So question one is what is "PXI system" likely referring to?? ..And to say more about it when you click the plus sign next to the "PXI system" entry it shows what appears to be a VISA resource name of PXIO::MEMACC. But again that shows up even with the card removed.
Back to the PCI card seemingly not being recognized I also read somewhere that there could be issues with this card and the new version of NI-DAQ 7.0. So I uninstalled that version from the machine and put on the version that came with the PCI card, NI-DAQ 6.9.3. But same story... Windows doesn't see it and unless this PXI system is somehow referring to this PCI card (??) then MAX doesn't seem to be seeing it either... Any advice on how to get this card up and running or how to truly troubleshoot to see if the card was dead out of the box?? ...Something I have never had happen before and somehow I still think it is just some silliness on my part...
Lastly, when I looked for the documentation for this card amont the long, long list of daq boards listed in the NI-DAQ software, nowhere did I find an entry for this PCI-6014 card. And I looked carefully. Does that mean I have a horribly old or outdated card??
Any help would be appreciated... thanks...

I am glad to hear that you got your card recognized correctly, too bad you have some bad PCI slots, though. The entry is shown by default and cannot be removed, but if you were to ever have a PXI chassis attached, your cards would be listed under this option, it is also where you would configure your controller and your chassis type. Also by default, there are no entries under this heading since you are not connected to a PXI system.
Andrew Mierau
Applications Engineer
National Instruments

Hardware-timed counting of two TTL sources with a pair of PCI-6014's

First, in a nutshell: I'm trying to count TTL pulses from two photon
detectors with short (.1-1 ms) integration times, for fluorescence
correlation spectroscopy. I have a pair of PCI-6014 DAQs, each with a
BNC breakout box.
First I created a LabView vi in which the counter from Dev1 outputs a
pulsetrain of the appropriate integration time, and then Dev1/CTR0 out
is physically routed to Dev2/PFI0 to time the acquisition of TTL pulses
on Dev2/CTR0. This seemed to work fine. The vi is attached below
(1_counter_works).
Then I added a second counter task, using Dev2/CTR1. Up until now
I've
been using a LabView vi in which I use this same idea, but with a
software-timed loop for integration times of >5ms. Software
timing
is too slow for shorter integration times, which is why I'm trying to
use hardware timing. But when I add the second channel, I
get the error "No DMA channels available", which is reasonable, I
guess, because each pci6014 only has one DMA channel. So then I
tried to measure and queue the data in one loop structure, then pass it
to a second loop structure to analyze and display the output (and
eventually I will also update a large data array). But I still
get the same DMA error. That vi is also attached below
(2_counters_queue_notworking). Perhaps I'm not doing the queueing
correctly. I also tried doing the counter measurement and
queueing sequentially in a flat sequence, but was unsuccessful.
This question seems to have come up several times recently, but not
with the exact hardware I have. I've looked through
this thread,
this one, and this one,
and haven't been able to solve the problem on my own.
Can anyone tell me if this is going to be possible with the hardware I have, and if so, how to go about employing queueing to
Attachments:
1_counter_works.vi ‏96 KB
2_counters_queue_notworking.vi ‏134 KB

Problem solved by adding a DAQmx channel properties step, specifying
the data transfer mechanism as 'Interrupts' instead of 'DMA'.

CROSS TALK - VIC FXO

Hi all,
I am facing the problem of cross call.
What happen is that,when someone is in a call and other people need to make a new call it dial to get voice tone, but it receive the cross talk (not the voice tone).
Someone known what could this?
The configuration is following:
voice-port 2/0
input gain 10
output attenuation 10
no vad
cptone BR
timeouts initial 4
timeouts call-disconnect 5
timeouts ringing 20
timeouts wait-release 5
timing sup-disconnect 1500
voice-port 2/1
input gain 10
output attenuation 10
no vad
cptone BR
timeouts initial 4
timeouts call-disconnect 5
timeouts ringing 20
timeouts wait-release 5
timing sup-disconnect 1500
Thanks

Please attach your entire running configurations. What version of IOS do you have? You may want to check CSCsg47594.

Cross talk

Hi,
I am trying to figure out cross-talk data for the different USRPs. I have seen some figures in this forum of ca -30 dB between Tx and Rx. Is this correct? In principle I am mostly interested in the coupling from Rx to Tx and -30 dB would be acceptable for my application, but I would like to have this confirmed.
BR,
Robert

This sounds in line with my experience. This post may help too.
I've tried things like transmitting with one USRP, and receiving on another...but it's not like you turn the Tx1/Rx1 chain 'off' if you just want to receive on the Rx2 path. So...you'll likely see the crosstalk anyway if you desire to transmit and receive on the same frequency.

I need to find a driver w/VI's that makes my PCI-6014

Can you send me a driver that will allow my PCI-6014 work with labview student 7.0?
Thanks
Greg

Greg,
The driver for our DAQ devices, NI-DAQ, is the same regardless of what version of LabVIEW you are using. You can download it free from this site:
http://digital.ni.com/softlib.nsf/webcategories/85256410006C055586256BBB002C128D?opendocument&node=132060_US
NI-DAQ 7.3.1 is the most recent version.
-Alan A.

Programmer's ref. manual for NI-PCI-6014 board?

Do you have programmers reference manual for NI-PCI-6014 data acquisition board?

NI-DAQ is the driver that interfaces with the PCI-6014. All of the NI-DAQ functions are described in the NI-DAQ Function Reference Online Help file. To view the NI-DAQ Function Reference Online Help, select Start»Programs»National Instruments»NI-DAQ»NI-DAQ Help.

Oscilloscope trigger on PCI 6014

Hi...
I tried to build triggered oscilloscope on PCI 6014 for educational purpose. First I build nontriggered Oscope13.vi and it works for me satisfactory. I can change oscillograme with time/sec and volts/sec, and measure values with cursors.
Then I want to trigger that Oscope13.vi with Analog SW Trigger.vi that I found in Cont Acq&Graph Voltage-Analog SW Trigger.vi example as subVi.
I built Oscope14.vi.
Now nothing works as i wanted. Time controls don't change oscillograme and it blinks (some kind of jitter).
Please, can anyone help me to get my nontriggered Oscope13.vi work also in triggered mode.
I work on LabVIEW 8 Full Developement.
Computer: Intel Pentium 4 CPU 2,00 GHz 1 GB RAM
Thanx in advance.
Damir Mileta

Damir,
first of all, the 6014 is a multifunction data acquisition device, not an oscilloscope.
I don't know where you got that example from as it is not following common implementation style guides.
That being said, i see that your DAQmx read returns an array of waveforms. This datatype contains the raw data and timing information. Your conversion of this to a 2D double array removes that timing information. So i assume that your waveform scaling functions runs rampart and messes things up.
Norbert

Signal cross talk on pci 6014?

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