Noise at analogue input of PCI-7350

Hi,
I have a set up as shown below.
Futek Load Cells >> SCC-SG04>> SC-2345 >>SH68-68EP Cable >> SCB-68 >> Analogue input of PCI 7350 8 axis motion controller.
This set up has resulted in a noisy analogue signal from 7350 with high amplitude spike.
I had try connecting the signal out of SCB-68 directly to an oscilloscope, and the signal was fairly clean without the spikes. however, when i connect the signal to AI of PCI-7350, both oscilloscope and load ADC.vi readings of the signal became noisy with high frequency noise on oscilloscope. All the AI ports and AIGND ports were probed without other connections showed the same noise problem.
Moreover, after the switching on of 24Vdc power supply for the motors, the amplitude of noise became even higher.
Is there any method to eliminate/minimise the noise pick up at the AI ports?? Any suggestions are welcome.
Thank you.
Yanxinix

An essential issue when connecting analogue lines to a system is connecting not only the signals lines properly but also the ground lines. Proper grounding of the signal connections is essential. You should be aware that BOTH lines (signal and GND) carry the signal, and depending on the connection of the GND line excessive current flowing through this line on a section between the system and the sensor may cause excessive noise. Much has been written about proper grounding of analogue signals. The most essential rule is NEVER to let any significant current (besides the current generated by the signal source) flow somewhere between the system and the sensor, i.e. NEVER use the signal GND lines as GND line for the power supply of the sensor. There are tutorials available on this issue on the NI site, try this one: http://zone.ni.com/devzone/cda/tut/p/id/3344.

Similar Messages

Large analogue input noise with laptop and 6024

Acquiring an analogue signal leads to large noise of +-100mV !
I'm using a NI 6024 card with shielded cable and a selfbuild connector box on a Dell D800 Laptop. The analogue inputs are used as differential inputs and connected to external amplifiers. In the box additionally the frequency output (GPCTR0_OUT and DGND) is connected to a small electronic circuit with an octal buffer (74HCT250) and 5V voltage regulator (An external 12V power supply is additionally used).
The noise is not reduced by connecting V_IN- directly or via 10k resistor to AIGIND.
There is no noise, if a battery is connected to the analogue input.
May I e.g. connect the DGND to the AIGND ?
I would be happy to receive any suggestions for solving
this problem.
Thanks a lot
Ralf

Hi Ralf,
When using laptops and external circuitry there's always a whole lot of noise generated by the conflicting coupling of the laptop's power source and your external source. You might find that using the external power supply but powering the laptop from the battery also helps. I'd suggest that first you make sure that your laptop and circuitry are powered from the same electric line, then you can connect your external digital ground to the AIGround via a 10K resistor, to protect the DAQ board. This will help, but I believe the best way will be to use a low pass filter between your amplifier and your Analog Input, that way you'll be able to get rid of most of the high frequency noise.
In general, if you have an external digital circuit powered by an e
xternal power source and you're using a laptop I recommend you use opto-couplers, powered by the 5V of the DAQ card to get rid of any possibility of noise.

Analogue input voltages railing to +/-32768

Adam
Hi,
I recently bought a RIO-7833R PCI card and am having weird problems with it.
I would like to use it to measure analogue voltages. However, even when nothing is connected to the card, the analogue input channels are railing to +/- 32768. I've written a very simple program to measure these voltages and it’s hard to see how there could be a bug in this code (see attached image). So, I'm thinking it has to be something with the driver of the card or some other bug in LabVIEW, or perhaps a setting on the card that needs to be changed.
Complicating things is that I actually had another card that was doing the same thing that I returned. When they sent me this brand new card it also gave the same values, so I do not think it is a hardware problem with the card. In addition, I've also changed the computer the card was installed in, and again, I get the same values.
Has anybody seen this before? Could there be a bug in the labview driver? I've tried changing the setup of the card in MAX so that the measurements are "differential” or “single ended,” but this does not appear to solve the problem.
Thanks,
Attachments:
FPGA problem.jpg ‏170 KB

Hi Adam,
I understand you are getting some strange readings from the analogue inputs on your NI PCI-7833R.
From what you say I agree that it is unlikely to be a problem with your specific piece of hardware. I have had a search to see if there are any known hardware faults for this device fitting your description and didn't get any results.
I don't believe the driver will be creating a problem for such a simple task as long as you have the correct one for your hardware and OS installed. You can check that it shows up in the software section in MAX.
I would suggest then that you try using the known working analogue input project for your device in the LabVIEW example finder which can be found on the start up screen.
In the example finder Select the Browse tab>>>Open the hardware folder>>>R Series>>> Basic IO>>>Analogue Input - R Series.lvproj. This has the FPGA VI to deploy to your hardware and a test Host VI. See if you can then get the expected 0 input when unconnected and test with a signal input on the graph.
Hope this helps
Jack. W
Applications Engineer
National Instruments

Synchronize analogue inputs with digital inputs

Dear fellows
I am using NI-DAQ, PCI-MIO-16E-4 (new name is 6040-E, I guess) with LabView 7.0. I am working on neuro-physiological signal acquisition. I have 16 analogue input channels and one digital input channel. Digital input is acquiring a TTL level signal that is a reference to the onset of a particular event. I want to synchronise both analogue and digital signals.
Any suggestion?
Nabeel

Nabeel,
have a look on following KB:
http://digital.ni.com/public.nsf/websearch/851A80A7AB2885E086256F4D000610E6?OpenDocument
(it's similar with DI)
regards,
ThSa
http://www.newgistics.com

Signal jitter in Analogue input using NI 9201

Have a signal issue in the system we're developing. I am using several NI 9201 analogue input modules in a 4unit chassis connected to a 7841R fpga with a 8110 Pxi controller. The 9201s are being used to measure the output of several contactless rotary sensors plus some force transducers and other signals. All sensors have the same isolated DC supply and noise is relatively small. The first rotary sensor of the six however at infrequent random occaisions gets quite large jitter, about +/-0.2v at a random frequency and the voltage appears to increase gradually. Measuring the input signal directly with a multimeter does not seem to have the same jitter or rise in voltage and no other signals are effected. When the sensor is unplugged and replugged the signal is normal again or after the FPGA is reset. It probably only happens once every 8 or so hours of use.
We had an identical issue with a previous system which used poentiometers instead of contactless rotary sensors. The only common hardware factor was that the problem only occurred on the first analogue input in a NI 9201 which is housed in the first slot on a 4u chassis. It is not the same 9201 module or chassis. Even the FPGA was a different model. All signals undergo the same filtering etc in the FPGA.
Has anyone had similar issues or have any suggestions on how I should investigate/resolve the issue.
Thanks in advance,
Andrew

Hi Andrew,
Thanks for your forum post regarding the jitter you are experiencing with your analogue measurements using the NI 9201. Having researched your issue I have come across the help file article here which details a potential cause of jitter due to resource contention on board the FPGA.
Basically the article describes that multiple requests on the same analogue input resource within the same FPGA clock cycle can introduce jitter, the jitter occurs most often when you use a shared subVI in two independent parts of the VI, or when you access a resource interface from parallel loops.
Please let me know if this assists in the debugging of your issue.
Many Thanks
Jamie S.
Jamie S.
Applications Engineer
National Instruments

Sample analogue input at preselected intervals

Hi a little help on this one would be great. I have an analogue input which only needs to be sampled at preselected intervals for example, the analogue input is rising from 0 upto a maxumum of 300 and needs to be sampled every 15 (amount selected on the sample interval selector) when 300 is reached it would stop. Could I use a pulse counter for this?

The sampling theory belongs to the time domain. In your project you have to set your sampling speed high enough to be sure you get the movement resolution you need. If you need some signal processing you also have to take this into consideration an increase the sampling rate. As an example. If you in your setting find a samplearte equal to 1 pr second to be adequate. You could of course use a sample rate equal to 1 pr sec. But you can remove a great deal of noise ( and then increase accuracy) by increasing the samplerate to say 100 pr sec, and then present a new value every second based on the average value of 100 samples
Besides which, my opinion is that Express VIs Carthage must be destroyed deleted
(Sorry no Labview "brag list" so far)

Inspire 5600 5.1 speakers, not enough analogue inputs on receiver? help!

Hi, I need some help connecting my computer up to my Inspire 5600 speakers. I want to set up an analogue 5.1 connection, as apparently surrouund sound in many games doesn't work with optical. My problem is with the inspire 5600 receiver. It only has analogue inputs for front and rear speakers, and none for centre/subwoofer. I tried using the Creative technical support site, but for some reason my speaker set isn't listed (it has the Inspire 5200, and the I-trigue 5600, but no Inspire 5600). I checked the guides for other speaker sets to see if they were relevant, but the flash animations all show 3 analogue inputs, not the 2 that my receiver has. My speakers are a few years old, and unfortunately I don't still have the documentation that came with them.
My question is where do I plug the centre/subwoofer? Does the Inspire 5600 not actually do 5.1 for analogue? (Aside from the analogue front/rear inputs, it has an optical in, digital din and a coaxial). Does the centre/sub maybe plug into one of these instead? I'm very confused, any help would be appreciated.

Sorry I mistook it for another model, my bad. The Inspire 5.1 Digital 5600 has only two analog inputs for front and rear channels respectively. You are right, there is no orange jack on the subwoofer for this model. Last I checked, I was told that this speaker model was released before sound cards with 5.1 connections came about. So if you are doing up an analog connection, you will lose the center/subwoofer channel. However if you own a Creative sound card, you might be able to enable the CMSS feature to create a virtual surround.

Recording from analogue input

using cool-edit or audacity. recording through mic input/output on left panel results in feedback howls from internal mic still active.have tried all combinations in sound manager settings.
can i record through usb input with phono to usb cable or do i need a analogue to digital converter?

Hello @8323,
Welcome to the HP Forums, I hope you enjoy your experience! To help you get the most out of the HP Forums I would like to direct your attention to the HP Forums Guide First Time Here? Learn How to Post and More.
I have read your post on how you are looking to record from an analogue input using recording software. I would be happy to assist you in this matter!
Are you recording audio with an analogue device while your internal microphone is still enabled in the sound manager? Is a howl sound made when you are recording with only the built-in microphone? In the meantime, I recommend following the steps in this document on Resolving microphone problems (Windows 8), which should help enable your system to record a better quality of audio.
Please re-post with the results of your troubleshooting, as well as the requested information above. I look forward to your reply!
Regards
MechPilot
I work on behalf of HP
Please click “Accept as Solution ” if you feel my post solved your issue, it will help others find the solution.
Click the “Kudos, Thumbs Up" on the right to say “Thanks” for helping!

How to address digital input & output, analogue input & output when communicate with mitsubishi fx1n plc

dear all,
i am new to labview, how to code or address digital input & output, analogue input & output when communicate with mitsubishi fx1n plc or crouzet plc.
pls help.
HM

http://search.mywebsearch.com/mywebsearch/redirect.jhtml?searchfor=mitsubishi+fx1n&cb=ZO&p2=%5EZO%5E...
Try the above link. I know it is a screen-full, but is a search result for Matrikon. They have a whole slew of OPC servers/clients you can try out. Personally, I would go with their OPC server for the Mitsubishi, and use Labview Datasockets. That would be the simplest with the lowest learning curve.
Otherwise, if you wish to use Modbus, you would have to get the commands/syntax from Mitsubishi; might be in their user manual, but I wouldn't lay bets on it. With the Matrikon stuff, the syntax is all built in.
Good luck which ever way you decide to go.
Dave

How to plot two analogue inputs from a DAQ device against eachother on an XY graph

I am trying to separate data I am acquiring from two analogue inputs on my NI USB-6009 in order to plot them againt one another on an XY graph. I have tried setting up two DAQ assistants on the block diagram, one acquiring data from ai0 and the other from ai1. I tried to wire these to the X input and Y input respectively and running in a while loop but Error -50103 shows up.
I've read through a few discussion threads and have found that you should acquire the data from both analogue inputs thorugh one DAQ assistant, useing index arrays to split the data and wire to the X input and Y input of the XY graph, but I cannot figure out how to do this.
Any help would be greatly appreciated!

It's pretty trivial to use a single DAQ Assistant. When you create one, you are given the option for multiple channels and shown how to select them. Once created with a single channel, you simply open the assistant and click on the Add button. After the acquisition, you use the spilt signal function if you stick with the evil dynamic data.

Connecting Parker's AR-08AE driver to PCI 7350 card

I have an Aries AR-08AE servo driver (by Parker) to drive a brushless servo motor (also by Parker). I have been unsuccessful at connecting the motor to the PCI 7350 card through a 68-pin screw terminal. I cannot get the motor to respond when i use the "interactive" section of MAX.
I have no prior experience with motion control. Can someone please explain to me the proper wiring configuration between these two devices. I've attached the pin diagram for the Drive I/O Connector of the Aries driver.
Thanks in advance
John Gillingham
Attachments:
AR-08AE_DriveIOConnector.pdf ‏481 KB

Hi John,
I don't have access to your drive or motor so I couldn't test this configuration, but it should work something like this to drive your servo motor. Make sure you double check our Manual for the 7350 Controller against the manual for the drive.
7350 Controller   Drive
Pin 6                   Pin 1
Pin 3                   Pin 21
Pin 32                Pin 14
Pin 31                Pin 15
Encoders:
Pin 36               Pin 3
Pin 3               Pin 4
Pin 37               Pin 5
Pin 3               Pin 6
Pin 38               Pin 7
Pin 3               Pin 8
That should be all you need to get it to work. Also make sure you check the Inhibit polarity from MAX to be sure Inhibt is not enabled when you are trying to do a move.
S. Arves S.
National Instruments
Applications Engineer

Analogue input for 30 inch Cinema Display?

Hi there,
I'm looking at getting a 30 inch Cinema Display and just wondered if there was a way to connect analogue sources (such as an xbox 360 for example) to the display. I guess what would be needed is a female DVI -> female AUX adaptor but I'm not sure if such a thing exists or if it would work the way I think?
If not, do you have any recommendations for good 30 inch displays that do have analogue inputs?
Thanks very much
Sam

The Apple display requires digital input. Dell has a 30" with analog and digital inputs
<http://accessories.us.dell.com/sna/products/Monitors/productdetail.aspx?c=us&l= en&s=bsd&cs=04&sku=223-4890>

Solely Analogue Input Sound Card?

Do these exist? I am looking for one with 8 plus analogue inputs? Any suggestions?

I have found this: http://tascam.com/product/us-2000/
But would there not be overload issues with recording 16 audio channels simultaneously through a USB 2.0 connection?

PCI-7350 replacement

I currently have a suspect PCI-7350 8-axis (part number 190975B-08) which is now obsolete I believe. I have two cards in one PC. Is a direct replacement available anywhere in the world or can I replace it with the PCI-7358 and simply use a new set of drivers which will deal with both cards, 7350 and 7358?
Thanks in advance

Hi rdl001,
Thank you for posting on the National Instruments forum.
The PCI-7358 is the replacement for the old 8-axis PCI-7350. I am afraid that you might not be able to get a replacement for the 7350 8-axis since it is now obsolete. So the best option would be to go with the latest one that is the 7358.
Hope this helps.
Shalini B
Applications Engineer
National Instruments UK & Ireland

Noise in thermocouple measurement using PCI-6024E DAQ card

I am using a PCI-6024E DAQ card for thermocouple(TC) measurement. The
TC is installed in the mold cavity of an injection molding (IM)
machine. The leads from the TC are connected to the DAQ card using a
CB-68LP board. I made a temperature mesurment task in LabView 7.0
with the two leads from TC as differential inputs and used CJC value of
25 deg C.
The problem is that when the IM machine is OFF, I get a reasonable temp
reading with some slight noise but as soon as I turn ON the IM machine,
the temp readings go wild with a lot of variations around the mean
value. The temp values also don't go to higher values when the TC is in
contact with the molten plastic in the IM machine.
Do I need to ground something here or put a resistor in the I/O board?
BTW the IM machine is grounded and the TC give correct temp values when
connected to a hand-held temp reader.
Any help will be highly appreciated.

Hello Aftab,
Looks like you need to use bias resistors to reduce the noise. Check out the following tutorial for more information about how to use bias resistors.

Noise at analogue input of PCI-7350

Similar Messages

Maybe you are looking for