All Sound Off (78H); Reset All Controllers (79H); All Notes Off (7Bh); Omni Off (7Ch) - Casio PX-5S Manual

Transmit Sent when an RPN, NRPN message send operation is performed.
Receive Receipt de-selects RPN, NRPN.
7.27 All Sound Off (78H)
Message Format:
n:
Receive Receipt stops all voices that are sounding.
7.28

Reset All Controllers (79H)

Message Format:
n:
Transmit Sent when MIDI send related settings are changed.
Receive Receipt initializes each performance controller.
7.29 All Notes Off (7BH)
Message Format:
n:
Transmit Sent when MIDI send related settings are changed.
Receive Receipt releases (key release) all voices that are sounding.
7.30 Omni Off (7CH)
Message Format:
n:
Receive Receipt performs the same operation as when All Notes Off is received.
7.31

Omni On (7DH)

Message Format:
n:
Receive Receipt performs the same operation as when All Notes Off is received.
7.32

Mono (7EH)

Message Format:
n:
BnH 78H 00H
MIDI Channel Number
BnH 79H 00H
MIDI Channel Number
BnH 7BH 00H
MIDI Channel Number
BnH 7CH 00H
MIDI Channel Number
BnH 7DH 00H
MIDI Channel Number
BnH 7EH 00H
MIDI Channel Number
21