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PCIe-6363 on Linux

November 26, 2017, 12:50 pm
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Dear all,

 

I'm interested in purchasing a PCIe-6363 to generate analog waveforms at high sample rates (e.g. > 1 MS/second). The machine in which I intend to install the board is running the latest version of Red Hat Enterprise Linux (7.4).

 

After looking into the driver situation, I'm a bit discouraged/surprised: the DAQmx driver does not seem to exist on Linux, only a basic version called "DAQmxbase" whose latest release is over 2 years old. This release does not mention PCIe-6363 in the list of supported devices. Furthermore, it seems that this basic version has some issues with DMA that might be problematic if high sample rate output is desired.

 

Can anyone clarify? Is NI simply not supporting Linux anymore? Or is there another driver I missed?

 

Thanks,
Wenzel

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Simultaneous use of DO and AI on SCB-68

November 26, 2017, 7:24 pm
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Hello! My name is Alexandra. I am trying to make my first device using labview. I'm using NI PCI-6221 and SCB-68 board. I need to measure an unknown resistance. I've made a voltage divider which must substitute several resistors of different values to the circuit, choose the closest value to the unknown one, and then show voltages over these two resistors on the graph. Supplied voltage for the divider comes from "5volts-fused" channel. To change load resistors I use digital out channels.

 

The problem is that it is not working properly((( Analog input channels show something wrong...  Measured supplied voltage using voltmeter and what labview measures through these channels are diffferent values((( How can it be? What am I doing wrong?( When I use only analog channels without using digital channels everything works perfectly...

 

Hope, someone can help me and understand my english) please!

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NI-9217 RTD Sampling Speed, High-Resolution vs High-Speed

November 27, 2017, 11:26 am
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Hello.  I am using a NI-9217 RTD module in a CDAQ-9178 chassis. What is the difference between High-Resolution and High-Speed on the NI-9217?

 

In my setup, I am sampling all four channels and realize the specified 800ms total for all four channels in high-resolution mode and the 10mS when in high-speed.  The acquired signal does have more noticeable noise in the high-speed mode.  

 

My question is what is happening when I select either mode?  Is a different low pass filter used in high-resolution mode?  Is high-resolution mode simply taking many samples and averaging?  Is high-speed mode dropping low order bits?  Just curious to what is going on [grin].  The NI-9217 manual is not clear to me what the tradeoffs are.

 

I need more speed and was curious if I could achieve similar results to high-resolution mode by using high-speed mode and average the data.

 

Thanks

 

Dan

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USB adaptor for PCMCIA 6024E card

November 27, 2017, 8:54 pm
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Of course i can realize you are finding it difficult to suppress a smile - yes i do have this 6024E DAQ card . Kind of a dinosaur in comparison with the new gen stuff. 

 

But then its in good working condition and there is no reason to scrap it just because the PC manufactures sabotaged the PCMCIA  slot !! 

 

Anyone use a USB adapter to interface this card ? In fact is one such adaptor there at all ??

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different Daq devices with 64/128 channel with sampling rate of 200 ksps per channel and min 14 bit resolution

November 27, 2017, 9:04 pm
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I need a Data Acquisition System  system with 128/132 channels (or 64 channels) ,simultaneous sampling at the rate of  200 ksps/ch or more with 500k/1GB memory and PCI/PCI 104 connector.
 
Also An output board is required with 128 (or 64)  output channels and DAC at 10 mhz with 1 K Memory/Buffer.
Kindly suggest some low cost options.
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low cost alternative of DAQ system 16/32 channel with sampling rate 200ksps/ch

November 27, 2017, 9:07 pm
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Kindly suggest some low cost alternatives of NI.

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Windows 10, USB 6009, and NI DAQmx base

November 14, 2017, 12:51 pm
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I'm having an annoying issue that started when I upgraded a machine from W7 to W10 and trying to get a USB-6009 to work under MX base (v15) on a computer that has both the full and the base versions of NI DAQ installed. The problem is that when the device is plugged in to the computer, the driver that is auto-installed is the one appropriate for the full version of MX, not the base version. Following the guide on the NI knowledgebase (Document 1, Document 2), I went into Device Manager, changed the driver to the USB Multifunction device, and then went to the MX base 'update firmware' application to send base-appropriate firmware to the device. This procedure works fine under Windows 7. However, Windows 10 does ...something during the firmware update process and immediately reinstalls the full MX driver, which of course is no help.

 

I can if need be rewrite my LabView code to use the full MX library, but I would prefer not to since this particular widget needs to be able to run on both a PC and a Mac and I'd rather not maintain a forked code base with two different driver libraries. 

 

Any thoughts or suggestions would be greatly appreciated.

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daqmx: Output analog signal and digital counter with varying frequency simultaneously

November 28, 2017, 10:01 am
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Dear all,

 

DAQmx provides a nice API to output a sequence of samples to one or more analog outputs (DAQmxWriteAnalogF64) and digital counters (DAQmxWriteCtrTicks, DAQmxWriteCtrFreq). 

 

I'm am wondering whether this functionality can be used simultaneously, for instance to output a stream of analog samples at medium frequency (e.g. 10 Khz) along with a counter output, whose frequency varies over time (and which is at much higher frequency, e.g. 10 Mhz)? I wasn't able to find any examples that are included with the DAQmx development SDK that use such functionality.

 

Essentially I'm wondering whether the following is legal:

 

task = DAQmxCreateTask(..);

analog_out = DAQmxCreateAOVoltageChan(..);

counter_out = DAQmxCreateCOPulseChanFreq(..);

 

/* Write a sequence of analog samples */

DAQmxWriteAnalogF64(..);

 

/* Write a sequence of counter frequencies */

DAQmxWriteCtrFreq(..);

 

/* Now send everything to the device */

DAQmxStartTask(..).

 

Any suggestions or alternative methods would be greatly appreciated.

 

Best,
Wenzel

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USB 6000 Digital I/O lines direction and status

November 29, 2017, 3:55 am
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Hello, I have just bought an USB 6000 and I am trying to read some Voltage values from the analog output through Labview.I created a Task and I can read the values as I want, but I have a problem with the configuration of the Digital I/O through Labview.

I configured the Digital I/O lines direction and status through the Measurement and Automation Explorer TestPanel (screenshot attached) but I would like to do this programmatically because each time i disconnect the USB cable or restart my computer these settings are gone.

I looked for some examples or some guides but I can't get this done even though it seems really easy.

I thought I could use the "DAQmx Set PowerUp States (Digital).vi" but when I do it i get error -200663 DAQmx Set Power Up States (Digital).vi<append>

Can you help me? Thanks!

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DAQmx Acquire real-time data from analog input channel and send acquired data to analog output channels simultaniously

November 29, 2017, 10:00 am
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Hello! I am new in Labview for data acquisition.
I have a NI USB 6259 DAQ (Labview Ver-2011).
I need to create DAQmx task that will continuously acquire data from (ai-0)
and send that acquired data, as it is, to output DAQ channels (ao-0 & ao-1) simultaneously, real-time.

input data (variable Frequency = 15Hz to 2KHz).
Anyone can help. I thank in advance for the help.
Regards,
Aamer.

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power supply to cdaq 9136

November 29, 2017, 2:37 pm
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Hi,

I have connected a dc power supply (24VDC) to my cdaq 9136. It's not powering on. Am I missing something?

I also found no tutorials on getting started with cdaq(regarding wiring, power supply etc)

Any help would be appreciated!

 

Thanks!

B

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daq connection

November 30, 2017, 4:47 am
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can i connect the output pins of  rotary encoder E50S8-360-3-T-24 to NI 6008 daq ?

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External Sample Clock with 2 sources

November 30, 2017, 4:55 am
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Hello,

 

I have the following HW and SW:

PCIe-6351

Rotary encoder - Signal A connected to PFI6 and Signal B connected to PFI5

Torque sensor

Labview 2015

DAQmx 17.0

 

My Problem:

I want to use an extenal signal for sampling my Torque measurement on a0. The sampling rate must be given by the A and B signals when going high.

So, every time either Signal "A" OR "B" goes high, then a measurement should be made.

The problem ist that I am not able to use 2 different sources for my sample clock.

Is there any way of doing this? Another question is: Is it possible to Sample by both rising and falling edges?

Encoder.JPG

 

 

 

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DAQ Grounding

December 1, 2017, 12:26 am
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Hello,

i have a question about DAQ grounding.

I use NI 9215 BNC + NI 9181.

Using the ground screw on the side ---> NI 9181 is grounded.

Because NI 9215 is connected to NI 9181 with the 15-pin D-SUB connector ---> NI 9215 is grounded.

My question is:

actually just the chassis of NI 9181 and NI 9215 are grounded.

But the channel and instrumentation implifier in NI 9215 are NOT grounded because of the channel-to-earth isolation.

In other words AIGND is isolated from this chassis grounding.

Am i right?

 

with best regards

Lei

grafik.png

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failed to read PWM signal generated by LabVIEW and DAQmx

December 2, 2017, 7:13 am
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Dear all,

 

I'm a beginner of Labview and DAQmx. I create a simulated NI PCI-6225 device and a virtual channel by using DAQmx. I want to use the counter of PCI-6225 to generate PWM signal, then display the waveform of PWM signal. I generate the PWM signal according to an NI example "pulse width modulation using NI_DAQmx and Labview" (http://www.ni.com/tutorial/2991/en/ ).

 

This example can't display digital waveform, so I add a DAQmx read module. Then there is an error " Error -200460. Read failed, because there are no channels in this task from which data can be read. Task Name: _unnamedTask<21>".

 

I tried different methods to modify the error, like add while loop, change sample rate, and so on. But, these don't work.

 

The problem may be simple, but because I'm a beginner, it's confusing to me. I've uploaded my .vi file. Hope to get help from you. Thanks a lot.

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NI myDAQ error -200284 using Bode Analyzer

December 2, 2017, 8:03 am
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Hello, 

 

I'm trying to use the Bode Analyzer from the NI ELVISmx Instrument Launcher to analyze a circuit I built. However, I receive an error stating that the samples I have requested have not yet been acquired. I read similar posts about this issue, but those solutions involve changing LabVIEW code. I'm just using the built-in Bode Analyzer, so I don't think there is anything I can change.  Is this correct?

 

Thank you,

John

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Simultaneous triggered read of analog and digital inputs

December 2, 2017, 8:53 am
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I am trying to write a DAQmx program (C#) that reads in a set number of points from various analog and digital channels from a PXI multifunction DAQ card. I want to start the acquisitions on the same trigger and collect an equal number of points at the some sample rate. I think I can setup an AnalogMultiChannelReader and a DigitalMultiChannelReader with appropriate clocks and then call ReadMultiSample on each to do this. The problem is that the trigger is external and it is possible it can arrive between starting each of the reads such that whichever process is called first is triggered but the other is not (presumably the time window here is very short but the triggers are very frequent and the program will run thousands of times so it seems it would be a possible bug). Is there a way to start both tasks simultaneously? Or a cleaner way to approach problem?

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IEPE microphone

December 3, 2017, 7:44 am
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I want to buy microphone for fault detection of rotating machinery. but I do not know that I must buy array microphone or free field microphone.

please help me

what kind of microphone is suitable for me?

what is the difference between these kind of microphone?

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How to connect thermocouples to NI DAQ USB-6225?

December 4, 2017, 10:38 am
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Dear all,

 

I am trying to connect some thermocouples to my existing NI DAQ USB-6225. The thermocouple is Type K probe see the link: https://www.mcmaster.com/#thermocouples/=1ajggrg

 

I am wondering if it is possible to do so. And if possible, what kind of connector should I use? And are there any other hardware I need to purchase?

 

I am new to hardware so I really appreciate all the help. Thank you very much.

 

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What DAQ System?

December 5, 2017, 6:21 am
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Hi Guys,

I'm looking to purchase a DAQ system for the attached piece of equipment. 

 

What would be best?

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