 <p>Although your device is capable of satisfying the usesdevice allocation, without a GPP or other ExecutableDevice, there is no place to run your component. There are two ways that allocation is performed when launching components:</p> <ul> <li>Satisfying usesdevice relationships</li> <li>Deciding on which device to deploy the executable</li> </ul> <p>Each implementation in the component's SPD has a list of dependencies that must be satisfied to run the entry point. Typically, for a C++ component, this will include the OS and processor type. Additional requirements can be defined based on the processing requirements of the component, such as memory or load average; these must be allocation properties known to the target device, just like with usesdevice. There is also an implicit requirement that the device selected for deployment should support the ExecutableDevice interface (there is slightly more nuance to it, but that's by far the most common case).</p> <p>When launching a waveform, the ApplicationFactory tries to allocate all required devices and select an implementation for each component in sequence. Each possible implementation is checked against all of the devices in the domain to see if there is a device that meets its dependencies. If so, the entry point for that implementation will be loaded onto the device and executed, and the ApplicationFactory moves on to the next component. If no suitable device can be found, it throws a CreateApplicationError, as you are seeing.</p> <p>For most cases, you can use the GPP device included with REDHAWK to support the execution of your components. You would usually only write your own ExecutableDevice if you have a specific type of hardware that does not work with GPP, like an FPGA. If you have installed from RPM, there should be a node tailored to your local system (e.g., processor type, Java and Python versions) in your $SDRROOT/dev/nodes directory. Otherwise you can create it yourself with the 'nodeconfig.py' script included with the GPP project; see the Ubuntu installation guide for an example (admittedly, somewhat buried in the REDHAWK Manual, Appendix E, Section 5).</p>