@radioscan - did you ever get your RSP1a up and running? If you haven't already done so, you will need to get the SDRplay API service installed. This is easily installed and tested via SDRuno or SDRconnect software. These software suites (from the
www.sdrplay.com website) will install the driver that is required for SDRplay radios.
After you get this running, now you can test with DSDplus. If you need additional help, I can send you batch files to get you up and running with DSDplus.