Frequently Asked Questions

Q: What causes okFrontPanel_LoadLibrary to fail?
There are a few reasons this call can fail and prevent loading of the FrontPanel DLL:
A.1: Make sure the DLL is in the current working directory of your application. Note that if you start your application from within Visual Studio, the application location and its current working directory may not be the same thing. You will need to check your project settings to find out.
A.2: Make sure the DLL architecture (32-bit / 64-bit) matches your application architecture (32-bit / 64-bit).
A.3: Make sure you have the Microsoft Visual C++ 2010 Redistributable installed. If you installed our FrontPanel SDK, you will. If you installed a driver-only version of this, you may need to install the redistributable separately. It can be downloaded for free from Microsoft. Be sure to match the architecture of the DLL to the architecture of the redistributable (32-bit / 64-bit)

Q: Does FrontPanel work with Visual Basic?
A: Yes! Our FrontPanel DLL will work with Visual Basic. Please visit this forum topic to see some user-contributed code that will help get you started.

Q: Does FrontPanel support isochronous USB transfers?
A: No. Isochronous transfers are typically used with streaming devices such as speakers, microphones, and webcams where the data delivery is not critical, but certain latency or bandwidth must be guaranteed. Isochronous transfers do not have any error-correction methods to guarantee the correct delivery of data. Bulk transfers (which FrontPanel uses) come with this guarantee baked right in.

Q: Do you sell or recommend any enclosures for your products?
A: We have an enclosure design for the Shuttle LX1 (XEM6006) which is available for volume purchase (500+). Unfortunately, we do not sell enclosures for our other products. Most of our customers integrate the modules onto their own design, so the enclosure would be application-specific. If you have found any enclosures that work particularly well, please email us. We’d be happy to list them here.

Q: What are the [NAICS, SIC, ECCN, HTS] codes for your products?
A: We use the following code references for our XEM products such as the XEM3010:
NAICS : 334119 – Other computer peripheral equipment manufacturing
SIC : 3557 – Computer Peripheral Equipment, Not Elsewhere Classified
ECCN : 3A001.a.7
HTS : 8473.30.20.00 – Parts and accessories of printed circuit assemblies

Q: How do I install a “minimal” FrontPanel system on Windows (i.e. just the drivers) ?
A: You can use our DriverOnly installer which is available on the installation CD and the Software Downloads forum. Simply have your installer call our driver-only installer during the installation process. Also note that our FrontPanel DLL depends on the Visual Studio 2010 redistributable that is architecture-specific. You will also need to install this redistributable along with your application. Please visit the Microsoft website for this free download.

Q: Using Java/Linux, I get an error java.lang.UnsatisfiedLinkError.
A: You must have the file located in your LD_LIBRARY_PATH. Alternatively, you can add ”.” to this path, but that may not be advisable for security reasons.

Q: Why does Windows run the driver installation wizard multiple times on the same device?
A: Windows runs the driver installation wizard whenever a USB device that reports a serial number (ours do) is plugged into a different port or when a different serial number device is attached. This can be disabled with a Registry Editor script such as:


Behavioral Simulation

Q: (ModelSim) There appears to be a problem opening the simulation library directory structure:

# ** Error: (vcom-7) Failed to open design unit file
"C:/mlibs/mapped/okFPsim_v2/fifoctlr_ic_v2/_primary.dat" in read mode.
# No such file or directory. (errno = ENOENT)

A: The library failed to open because it was incompatible with your version of ModelSim XE which is unable to refresh libraries compiled with a different of the software. Opal Kelly tries to maintain a release of the simulation libraries using the latest free ModelSim XE. These packages are available in either the installed FrontPanel application directory, or are available for download through our online forum. We do not typically support older versions of ModelSim XE because upgrading is free.

Most versions of ModelSim SE and PE can automatically refresh our libraries generated by ModelSim XE upon first use. You will see a string of warning messages, but the library will then overwritten with the refreshed data and not produce warnings with repeat use.

Q: (ModelSim) The simulation architecture is not loading:

# ** Error: (vsim-3173) Entity './work.okhostinterfacecore' has no architecture.
# ** Error: (vsim-3173) Entity './work.okwirein' has no architecture.

A: The Opal Kelly FrontPanel simulation libraries are either not mapped properly to ModelSim, or you are not linking to the library when starting the simulation. For help with both of these problems, please see the ModelSim tutorial, or examine some the FrontPanel sample applications included in the FrontPanel installation that include a /simulation subfolder.