Hi Duurduur,
MobileSheets supports the 'new' and easy way of linking songs to registrationfiles, that was introduced in Genos and is also supported in the PSR SX range, so linking songs and registration files is now very easy.
One time actions :
1) Load the 'All Parts' Midi configuration file on your PSR SX keyboard. It should come that way from the factory, but it can't hurt checking if that has not been changed.
2) Tell MobileSheets you are using a Genos or PSR SX keyboard. To do that, go to Settings/Midi settings/Midi Device Type (or Instellingen/MIDI instellingen/MIDI toestel in Dutch ) and select Genos PSR-SX .....
Then for every song, (while tablet and keyboard are connected to each other)
Load the registration file and optionally press a registration button on the keyboard.
Load or select the corresponding song in Mobilesheets and go to the Edit screen to change song settings. Select the MIDI tab in the edit screen
To establish the link, just press the chain icon at the right of the MIDI Tab screen. (it's the bottom one of the 4 icons there) and press 'OK'
That's it! Now they are linked.
And as mentioned before in this thread the link works both ways.
Good luck!
Rudy