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

Similar Questions

• 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

  
  

• 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

• Mapping of Signal USB-8451 problem

  I recently bought a USB-8451 used to try some Labview SPI/I2C development. I found that when I create a simple VI to write and watch the signals on a PC based Logic Analyzer, I see that the SCLK, MOSI lines are reversed. I checked that I have the correct connections to the Analyzer and confirmed that the pins are correct in the 8451 user manual. If someone else found this? I've attached screenshots of my VI and Logic Analyzer. I tried the 8451 examples and the result is the same, the SCLK appears on the MOSI line. I don't think it would be a real issue of what I want to do, but I find it strange. Am I missing something?

  Catherine,

  I found the problem. After the change to a faster USB port and to monitor and increase the frequency of sampling, I was able to get the SCLK appear correctly. I can say that this problem is resolved,

  Thank you

  Andrew

• It is possible to contact PCA9548A (8-CHANNEL I2C SWITCH) using USB-8451?

  Hello

  Now, I'm doing a project related to the smart battery. Now, I read data from a stack using the USB-8451 by smbus. The next step uses the USB-8451 casing to read the data of several batteries through smbus. I chose the PCA9548A (8-CHANNEL I2C SWITCH) to achieve this goal. But when I check the specification of the PCA9548A, there is a fix I2c format to read data from it, I tried several times, but still no can tell me where is the error in my code, or maybe it's impossible to communicate with this chip using USB-8451?

  Here is the fix that i2c read format of PCA9548A

  Why are you usng the script live? Have you looked at the examples of delivery for the 8451? You just need a couple of nodes property to set the rate and the address, and then use the VI to write I2C.

• Access USB on Toshiba 40L5435DG

  Hello

  I just buyed TV Toshiba 40L5435DG and ther is a problem of concern to access USB.
  When I plug a USB on TV, I can access it without problem for the container, but if I go to the TV or other connected device, I can't go back to USB.

  I have to unplug and plug the USB key again in order to access the contanining!

  Any solution for this? The firmware update can be...? Or it's normal...

  Thank you very much

  Josean

  It is really strange. With the help of option for media player, you should be able to appreciate the content saved on your USB, but of course you must tell your reader what type of files you want to see.

  What I know of my Toshiba TV:
  -Do not insert/remove the USB device during use.
  -MENU is probably not available during playback.
  -When you want to use your TV as a Media Converter, a Media Renderer on

  Can you please test again and post comments?

• 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.

• 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.

• 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.

• NEITHER USB-8451 with external power source

  Hi all!

  I try to understand for 2 days now why my USB-8451 gave me a 301740 error: line SDA or SCL or both are in poor condition, or there is no pull-up resistance.

  I try to change a multiplexer channel in order to obtain a measure of the temperature of a sensor. I checked my SDA and SCL lines, thye are both in top condition and I have 2 resistors to pull up with a value of 10K.

  The only change with my older circuit, is I use an external power supply for my chip and a PCA9543 (texas instruments) MUX to select the sensor I need the data.

  Any who have encountered similar problems?

  OK guys,

  Apparently, the ground of my usb-8451 was not related to the land of my diet, it doesn't yet but my components react!

• 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

• PC crashes when loading driver NI USB-8451

  We bought a unit of SPI NI USB-8451. First of all connected to the computer, a message appears asking to load the driver concerned. I have it to point to \Program Files\National Instruments\NI-845x\staging\ni845x.inf which it loads but then immediately causes the PC to break and restart (PC uses Windows XP). Try it on another PC gives the blue screen message of problem with the file "Diego.sys". The version of the driver is the last (v1.1.2). I tried to download older versions of the driver from the Web site of NOR, but when it is installed the \staging directory with the file ni845x.inf does not (some confrontation with newer versions of MAX?), therefore could not tell if they made a difference. Do you have suggestions about the problem? Thank you

  Richard.

  Problem solved by removing USB Safend protector software

• 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.

• 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.