Hi deepak87,
PSR-S, SX and Tyros models as well as Genos have two internal MIDI ports (2 * 16 MIDI channels). So there are 16 channels for MIDI files (Song parts) which are completely independent from the remaining 16 channels (which are used for up to 4 Keyboard parts, 4 Multi Pad parts and 8 Style parts).
INTERNALLY it is NOT possible to route channels (parts) from MIDI files to keyboard parts. Theoretically, however, this would be possible using a so-called "MIDI loop", i.e. a DIN-MIDI cable that connects a MIDI OUT to a MIDI IN of the keyboard. In principle, however, I strongly advise against this option. Instead, I recommend editing the MIDI file in question, e.g. in the free "MixMaster" PC program, a MIDI Sequencer program (DAW) or in "XGWorks" on the computer or directly on the keyboard. I often use "Midifile Optimizer XI" by the German company Midiland for easy editing MIDI files.
In order to get a Panel Sustain effect, the value of the "Release Time" parameter must be increased on the relevant MIDI channel. If this parameter is not already there, it must of course be inserted first (usually in the initialization bar of the MIDI file, i.e. bar 1).
Hope this helps!
Best regards,
Chris