Device USB-8451 reference and attached device

Similar Questions

• I2C communication slows down over time using USB-8451

  Hi all!

  I try to communicate via a device slave using a USB-8451 I2C and I noticed that after a while the communication speed slows way.

  I can send and receive data very well and apparently my system seems to work. But the problem is that over time the speed of data transfer slows down so much so that if I let it run all night it has slowed to a crawl in the morning. My ultimate goal is to gather data, draw and save every second and at the beginning it is easily achievable, but after 10-15 hours I can no longer collect data as fast I need. I'm not quite sure if this is a problem with my code LabVIEW, the NI USB-8451 box or the slave device. But if I stop running the LabVIEW program and start it again, everything returns to normal.

  The slave device is a personalized card with a microchip PIC which acts as a slave I2C and returns the data at the request of the master. I can't imagine anyone will be able to determine if this is a problem directly, but if we can rule out the other two (code LabVIEW or the NOR-8451) as the source of the problem so I know it's my slave device.

  I've greatly simplified the LabVIEW code that I used to collect data on I2C and I see even this gradual slowing down over time. Attached, it's that the very simplified VI and the data file, it produced. I only ran it for about 45 minutes, but from the beginning to the end we see again that the enforcement timeframe is rising.

  I hope I'm just doing something stupid, thanks in advance!

  -Aaron

  Aaron,

  Do not have the additional module responsible for these functions, but I'm sure I know whats going on.  It seems that each time through the loop 'OR-845 x I2C Create Configuration Reference.vi' creates a new reference.  After a while it will start to slow things down.  Better to open the reference before the while loop starts and spend just the reference in the loop.  Don't forget to close the reference after the loop stops.

• Ground and the USB-8451-> it should reference?

  I use a usb-8451 attached to a PCB card which has its own means with separate analog and digital designs. When I join the 8451 grounded strange results of power supply occur. Is it allowed to leave separate and unconnected?

  Devices USB usually get their power supply (+ 5V and GND) of the device, they are connected. There is no need of additional connections to GND. These additional connections can lead to "mass loops" that can pick up noise and cause errors. -The 'front end' of a device properly designed USB is isolated from the power supply. If you connect anything to the input of the USB device, use the GND or NOT the entrance terminal, of reference and NEVER the Terminal GND of the Board that powers the USB device.

• I get the message "device USB has malfunctioned and windows does not recognize it" when I connect my Ipod touch to load or put music on it.

  Original title: legacy A USB has malfunctioned and windows cannot recognize him does that mean?

  I get this message when I connect my ipod touch to load or put music on it. It worked before on both of my computers and I have not changed anything on one of them. I even bought a new usb cords just in case that was the problem, but still no luck. the funny this is that the battery in the corner of the ipod looks like he got some fees, but I'm not sure because of the message. I soft reset it and hard reset it I tried to install the new updates, but it is said that it is up-to-date. It is therefore unknown on my computer device how do I? someone please help.

  Hello
   
  The problem is specific to the Ipod?
   
  I wish that you follow all the steps in the article apple to fix the problem.
  http://support.Apple.com/kb/TS1538?viewlocale=en_US
   
  Aziz Nadeem - Microsoft Support

  [If this post was helpful, please click the button "Vote as helpful" (green triangle). If it can help solve your problem, click on the button 'Propose as answer' or 'mark as answer '. [By proposing / marking a post as answer or useful you help others find the answer more quickly.]

• GPIB-USB-HS and USB-8451 communication issues - appearing only in VISA

  Hello

  I recently started a new job and have had communication problems between my adapter GPIB-USB-HS, my VISA or MAX-Labview and USB-8451 I2C/SPI interface.  I installed LabView to 32 bits, OR-488. 2, the driver for the 8451 on my windows desktop and VISA 16.0 7.

  In the windows Device Manager, the 8451 appears as a device USB of NI-VISA and Gbspecifications FOR-USB-HS presents itself as a GPIB Interface of NOR.  Two of these instruments are recognized NI Max so but communication Gbspecifications FOR add-in adapter (and connected instruments) fails and he can't find the instruments and the self-test fails with a hardware error unknown gpib (-37052).  The watch also neither device VISA Interactive Control.

  The ready light is lit on the GPIB-USB adapter and the 8451 flashes green as if nothing is wrong at the end.  I uninstalled all the software of NOR and reinstalled, and I run MAX as an administrator.  Is there possibly some computer settings I could neglect or need to change to open a communication?  Any other ideas on why I can't communicate with devices?

  Thank you!

  Trey

  This is a device-Lock software that my it was preinstalled on the computer blocks the USB port.  SHE has added features like confidence, and now it works.

• Compatibility DAQmx and NOT USB-8451

  NEITHER USB-8451 is compatible with NOR-DAQmx?

  The USB-8451 housing does not NOR-DAQmx; It uses a separate driver and API (OR-845 x; ( the latest version is 2.0).

  It is compatible in the sense that you might have OR-DAQmx and NOR-845 x installed at the same time, because they are two independent pieces of software. It is not compatible in the sense that you cannot use the USB-8451 with the API OR-DAQmx case.

• USB-8451

  Hello

  I am trying to contact a gyroscope using NI USB-8451, I used the example of "General I2c Read.vi" trying to communicate with the device but I get different errors each time that I run the program, I used the gyroscope with my Arduino board and it works perfectly, attached, I the datasheet and sample Arduino code of the gyroscope. Any help would be greatly appreciated.

  4K should be good. For moderate transfer speeds you can probably get with somewhere between 3 k - 10 k. I think I use 4.7 k often because I have, but it's really not too picky. The Arduino (I think) has a few weak pull-up (20 k - 40 k?), which probably explains why you had some communication, but I'd be surprised if it was robust as the waves will probably not be very pretty.

  This has some pretty good photos of different traction I2C and the effect on the wave form: http://dsscircuits.com/articles/effects-of-varying-i2c-pull-up-resistors.html

• USB-8451 presents itself as a COM RS-485 port

  Hello

  A system that I worked for 6 months just had a strange problem... I set up a USB-8451 device to the MAX with an alias VISA and was able to use it for the last few months with no problems.

  Last week I noticed errors when the device was admitted in LabVIEW, so I checked its configuration in MAX. It is now identified as a port COM RS-485, not as a USB device.

  

  He is also identified in the Windows Device Manager (Vista) as a COM port:

  

  I work at remote system for now, so all I tried to do is to uninstall and reinstall the device in Device Manager. I thought next to find someone on the spot to put the card, remove it to MAX and then try again.

  Any other suggestions?

  Thank you

  Martin

  Are you sure that you do not have a USB-485 device attached to the system in addition to the USB-8451? So that NEITHER Serial recognize a device such as a USB-485, he should be able to load firmware USB-485 to the device successfully and to communicate properly with him. The USB-485 and USB-8451 are very different hardware architectures, so I would find that very unlikely.

  -Jason S.

• Read only the SPI using the box USB-8451

  I am using the NI USB-8451 box to read the SPI of a Honeywell digital pressure transducer data.  The difficulty comes from that part of Honeywell uses only the SPI in half-duplex mode, meaning that it only transmits data, but does not require anything beyond the appropriate chip select signal and SCLK to start transmitting its 32-bit sensor data.  To facilitate experimentation with the sensor, I bought a USB-8451 SPI Interface thinking I could easily configure the 8451 to read data from the sensor.

  However, if I understand the situation, there is a problem.  The 8451 considers full duplex data, i.e. a data word must first be sent to the SPI device in question before the unit will start to transmit back data of its own.  And since the MOSI data writing periods, since this particular device starts transmitting immediately once a clock is applied, synchronizing the unused address data will cause the unit will return its data before the 8451 begins listening for data in return.  The call used by the 8451 to write read action can be divided into the individual reading and actions of writing of any kind that I could discover.

  Can someone tell me if I missed something in this operation or if there is some quick tips, that I could use to be able to use the 8451 therefor?  Thank you!

  Doug G.

  Exactly correct. It's nice when things are easier than expected. Hope it works as easy as it sounds.

• Tutorial or examples to access USB-8451 in LabWindows/CVI by C

  Hello

  I can't find any tutorials or C NI USB-8451 access with the compiler LabWindows of coding examples. I see the user manual containing several functions to find the device, etc., but there is no example code for control functions and how to use them. I was wondering if it does not exist anywhere, or if someone could help me am began simply access to him and some of his DIO functions? The code to access the USB should go in the source C code to .uir interface?

  Thank you for any assistance.

  OR claims that there is an example for the CVI (for XP in the folder C:\Program NIUninstaller Instruments\CVIXX\samples\ni845x) - after you download the driver I did not have this material so I can not myself...

• USB-8451 I2C slave?

  I have a camera that I have to test that uses the I2C bus.

  The device is a card with a microprocesssor on what is a master I2C

  The USB-8451 case maybe an I2C slave?

  Hi RTSLVU.

  Unfortunately, the box USB-8451 can currently work as a slave on the I2C or SPI bus. Be sure to visit the Centre of Suggestion of product and submitting this function as a product request. The more suggestions that are made, most likely is that this feature is implemented in a future version of the material.

  Best regards

  John M

• USB-8451 I2C for

  Hello

  I am looking for a starting point.

  My problem is that I have to communicate with the PCA9555 (http://focus.ti.com/lit/ds/symlink/pca9555.pdf). I searched the site of NOR and have met a USB-8451, which seems to be the answer to my problem.  However, I also have to measure current and this device seems to lack this ability.

  First of all, it would be the device that I would like to use to communicate via I2C? The only reason why I have a question is because I can't access the examples that would give me a good idea that I found what I was looking for.

  Second, is there a device like this one offered by OR who would be able to communicate via I2C and be able to measure current? Or what I need to buy 2 separate devices?

  Thirdly, is there anyone out there who has encountered the same problem (possibly with the same PCA9555)?

  Thank you

  Gerardo Hernandez

  
  

• NOR-USB-8451 fails after spending a lot of time

  Hello, I use a NOR-USB-8451 contact a panel using SPI (8451 scripting).  NOR-USB is master and slaves are all (EEPROM, ADC and DAC) ICs on the Board of Directors.   If I run my ATP in a loop of 10 times the 8451 will fail at the same point on the 8th time the test is run. When the problem occurs all SPI tests after this point will fail and the test of the 9th and 10th runs fails entirely SPI.  If I remove the USB cable connected to the 8451 and re-connect it works properly again.  If I run my loop it will fail again at the same point.  It seems to me that there is a kind of problem of overflow here.  I tried to add a Script Reset before all the build scripts, but it doesn't seem to work.  I use CVI 8.1 to create the DLL referenced by TestStand 4.0.

  Any help will be appreciated.

  Nazar

  JGB Consulting, Inc.

  As it turns out, it's a mistake to programming on my part and not a problem with the device OR-USB-8451.   I was building scripts of SPI with CVI, two of my scripts did not contain a CloseDevice call.  This is what caused the error.  Fixed all the CloseDevice to these scripts added.

• Gyro I2C OR USB-8451

  Hello

  I finally got my Gyro to work with the NI USB-8451, but for some reason any I get a lot of noise from my signal outputs. I guess I have do some bit-operation wrong somewhere, attached I have my VI, can a you experts out there, take a look and see if I'm good things?

  (You can look at my previous thread for reference)

  Thanks in advance

  Never mind got it right it was not only signed bit instead of signing.

• USB-8451 does not appear in the menu of the DAQ assistant

  Hello

  I use a USB-8451 with LabVIEW 8.6 device. I installed the 1.1.4 pilots of this device and windows and MAX detect. I also renamed the alias and the status of the device is "this device works correctly.

  The problem comes when I try to add a block DAQ Assistant to my project. I select the entry type, I want to have (digital line, although I've tried them all) and LabVIEW doesn't detect any device.

  I tried to make a diagnosis with Panel Test VISA. Here, I assume that something is wrong, because when I run a viRead I get status of return 'BFFF0015h' in red letters... but I don't really know what that means. The LED on the device is green and flashes.

  Thank you in advance.

  It is not supposed to appear in the DAQ Assistant (and certainly won't NI-VISA) or if you have not read the Manual?