Samick SSP30 Owner's Manual page 22

USB_LOCL OFF
Press the MIDI button again to select the PROGRAM CHANGE On/Off
PGM ON
PGM OFF
Press the MIDI button again to select the PROGRAM CHANGE On/Off
CTL ON
CTL OFF
The instrument will not send the songs of the USB disk to the internal tone
generator but will send all the midi information from the Midi Out of the
instrument.
This configuration will allow the instrument to send and receive the Program
Change Midi information.
This configuration will NOT allow the instrument to send and receive the
Program Change Midi information.
This configuration will allow the instrument to send and receive the Control
Change Midi information.
This configuration will NOT allow the instrument to send and receive the
Control Change Midi information.
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