Post Go back to editing

AD7745 used via LabVIEW on a Win7 PC

Hey guys,

I am new to this forum and hope you can answer my questions about using an AD7745 ADC in a LabVIEW environment.

We used this chip for a while now under WinXP, but since the support for this OS will terminate soon our university requires that we move to a newer version of Windows. We migrated our LabView framework to a 64bit Win7 Enterprise which did work out fine.

Now we have the problem that the dll library for the AD7745 for the new OS is different from the one used for XP. Therefore our implementation does not work - most likely because LabView tries to send the wrong commands to the board. I did write to the support if they could provide us with an interface to access the library and see how the basic functions work in order to implement them in LabView (which we did before for the XP as well), but they 'refused' to help so far.

Does anyone have experience with this kind of problem? Or even better, has anybody done this and could send me a copy of their LabView VI?

Kind Regards,

Faja

  • Hey Sean,

    yes I did download the software and it is also able to read the board - so hardware works and windows uses the right drivers.

    My problem is that I don't have any information how to adress the board through LabView. The Code we have from XP is not able to communicate correctly. In the XP version of the .dll library have been 2 functions LoadFirmware and DeveloperRequest (or something similar). The new version of the library does contain 6-8 (not sure right now) different functions, where I do not know how they work exactly.

    Is there a way to get this information from the software?

    Regards,

    Faja

    P.S.: Thanks for the fast answer!

  • Hello Faja,

    Are you talking about the evaluation board?

    The software downloadable from the AD7746 evaluation board page should help you with this:

    http://www.analog.com/en/analog-to-digital-converters/ad-converters/ad7746/products/EVAL-AD7746/eb.html

    This download contains both 32-bit and 64-bit compatible software.

    Regards,

    Sean

  • Hello Sean,

    thanks again for your fast reply and help!


    The vi's you attached did help us, but we still would need at least the "vendor request.vi" if possible ("download Firmware" is asking for it).

    You told me that it is not possible to provide any information on the dll functions used for the cdc. I will forward what my colleague asked, since I might not have been clear about what we need. 
    We would need a programming reference for the functions in the dll library, i.e.:
      1) function prototype (i.e. return_type name(typ1 par1, type2 par2...). This can usually be derived from an appropriate header file (used to be *.h or *.hpp in C++).

      2) a description what the parameters are and
      3) a description what the function does (and what it does not do, if important).
     

    I wanted to ask this again in order to avoid misunderstanding on what we want. If you could send me the vendor request vi I would greatly appreciate it and maybe there is a way to get the other information as well.

    Thanks again for your support and have a nice evening.

    Regards,

    Faja

  • Hello Faja,

    The evaluation system contains our CDC component, which we want the customers to evaluate and to which we are, of course, prepared to provide full support for.

     

    The evaluation system also includes a third party (Cypress) USB microcontroller in order to allow connection to PC via the today's most common USB interface. We provide user interface software for the PC to use the evaluation setup in order to perform data acquisition and basic analysis.

                         

    We cannot support a connection of the Cypress uC via the USB interface to customer specific system, a system which is to us unknown and unspecified. We have only limited knowledge of the Cypress controller and drivers ourselves, the DLL that we use on PC are very little documented. We cannot provide support for that third party component in our evaluation system.

     

    However it is possible to make some Labview example code available. This Labview example code uses all components required to access the CDC on the evaluation board via Labview on the PC. The overall functionality can be adapted by yourself.

    Find attached the VI that enables the firmware download using the Cypress dll. Note the use of a handle to specify the target system.

    Regards,

    Sean

    AD7746Rev3-0_Example.zip
  • Hello Faja,

    I missed the vendor_request  VI. I have updated the zip file.

    Regards,


    Sean

    AD7746Rev3-0_Example.zip
  • Hey Sean,

    thank you for the help, really appreciate it!

    Wish you merry christmas and a happy new year!

    Regards,

    Faja

  • Dear Sean,

    unfortunately I have another question regarding the .vi's you gave to me. In the vendor_request.vi the comments mention, that most of the communication follows functions written by cypress. Could you give me the ID of the part build onto your evaluation board? So I could contact cypress and see about the documentation for this chip.

    Again merry christmas!

    Regards,

    Faja

  • Hello Faja,

    Happy Christmas to you.

    I don't have access to the VI during the Christmas shut down, so I can't confirm the information in the VI you are talking about.

    However, the part number of the Cyress controller is given in the Evaluation guide:

    Microcontroller, EZ-USB FX2LP, 56-lead QFN Cypress CY7C68013A-56LFXC

    Kind regards,

    Sean

  • Dear Sean,

    our institute was closed down as well, therefore my late reply on the matter.

    Thanks for the information - unfortunately I have some trouble once more.

    Additional to the vi's you gave me there are two more (write_reg.vi and read_reg.vi) which are used within the old labView code. These call the vendor_request.vi to read/write to the eval board of the AD7746. Sadly the call parameters have changed and the documentation is not clear on which parameters need to be passed to vendor_request.vi in order to perform a read/write operation.

    Are there newer versions of read_reg and write_reg you could send to me? If not is there any information on the parameters needed for vendor request to perform the read/write operation?

    Happy belated new years to you!

    Kind regards,

    Faja

  • Hello Faja,

    Find following a description of the requirements for the I2C interface:

    Handle:- Passed by connect.vi

    ucRequest:- 0xDD; Defines I2C 8-bit pointer protocol

    usValue:- 0x90; I2C address of AD7745

    usIndex:- 0xXX; Register address

    ucDirection:- 0 or 1; 0 = PC to EZUSB, 1 = EZUSB to PC

    usBuffer_Length:-1 to 64; Number of bytes to transfer, max = 64

    ucBuffer:- Array of data to transfer

    I hope this helps.

    Regards,

    Sean