How to list OPOS Biometric devices installed? RRS feed

  • Question

  • I installed U.are.U 4500 fingerprint sensor drivers from here

    Inside the folder it was installed it came with an OPOS project sample (created in visual basic) wich I already tested and it is working fine, so I tested my next code to get to work with the OPOS device:

    List<string> retorno = new List<string>();
    PosExplorer myPosExplorer = new PosExplorer();
    DeviceCollection myDevices = myPosExplorer.GetDevices();
    foreach (DeviceInfo dev in myDevices)
        if (dev.Type == DeviceType.Biometrics)

    For some reason this code does not find any biometric device. I know that this method work for other OPOS devices (like Msr, Scale, LineDisplay). But why it can not find the biometrics and the sample code it is able to do it? Am I missing something?

    PS: I am working with c#, WPF and OPOS framework 1.14.

    • Edited by Carlosfer02 Monday, September 3, 2018 10:46 PM
    Monday, September 3, 2018 10:45 PM

All replies

  • Hi Carlosfer02,

    Thank you for posting here.

    For your question, what is the type of your device? If you want to get the OPOS device, the type must be "POSPrinter".

    For more details, you could refer to the following links.

    Best Regards,


    MSDN Community Support
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    • Proposed as answer by Stanly Fan Thursday, September 27, 2018 6:15 AM
    Tuesday, September 4, 2018 5:50 AM
  • @Carlosfer02,

    It appears that you may be attempting to access Biometrics devices using OPOS service objects through POS for .NET compatibility layer.  You may find the following article valuable:

    However, please note, POS for .NET does not support OPOS compatibility for Biometrics devices.  Please see the following link for a full list of OPOS devices supported through POS for .Net.

    You will either need to use OPOS directly without going through POS for .Net or obtain a POS for .Net service object from the device vendor.

    Terry Warwick

    Sunday, September 9, 2018 4:59 PM
  • By the way, Mr. Warwick.  

    The BiometricInformationRecord defined in POS for.NET seems to be missing some information below from UnifiedPOS definition.  

    - Quality

    - ProductID (Owner, Type)  
    - Subtype  
    - Index Flag  
    - Index(UUID)  

    - Digital Signature  

    Then it seems that the information on the creation date and time is not the time the device read, but the date and time that the BIR object was created in POS for.NET.  

    As a result, using OPOS via POS for.NET or device vendor developing POS for.NET service object may have some problems remaining due to these differences and it may not possible to be successful.  

    • Edited by Kunif3 Friday, October 5, 2018 2:20 PM
    Friday, October 5, 2018 11:41 AM
  • @Kunif3,

    What information leads you to believe that the BiometricsInformationRecord property in POS for .NET does not support these elements?

    Terry Warwick, Microsoft

    Friday, October 5, 2018 3:17 PM
  • @Warwick,

    It is based on the comparison of the BiometricsInformationRecord description page of the Micrsoft document site and the UnifiedPOS specification.  

    BiometricsInformationRecord Members (POS for .NET v1.12 SDK Documentation)

    I was interested in this question on the StackOverflow site and I noticed that I was making a conversion program.  

    It will not appear in the intellisense information of Visual Studio, so even if it exists inside, it will not be published to the application developer nor to the service object developer.  

    Since I published the created program below, please look if you are interested.  


    Saturday, October 6, 2018 4:22 AM
  • @Kunif3,

    We have confirmed that the BiometricsInformationRecord in POS for .NET is missing fields from the Header section as well as access to the digital signature.  To my knowledge this is the first time that anyone has encountered this issue in POS for .NET, which leads me to believe that other Biometrics implementations are using Windows Biometric Framework rather than POS for .NET.

    Do you have a customer that you are working with to enable Biometric via POS for .NET?

    Terry Warwick, Microsoft

    Wednesday, October 10, 2018 6:04 PM
  • @Warwick,  

    Or, if they are optional information, developers may be adjusting to work without them.  

    Customers of Biometrics devices may occur in the future.  

    Because, at the OMG meeting last month, OPOS-J should propose addition of robot-related communication device function to UnifiedPOS.  
    Among them, there is the possibility of expanding and using the UnifiedPOS Biometrics device to identify shoppers.  

    The application actually uses WS-POS, and it will be in the form of using the POS for.NET Biometrics device via the service provider of the WS-POS reference implementation.  

    Please ask OPOS-J for the latest detailed information.  
    Wednesday, October 10, 2018 10:56 PM