Casio AP-400 - Manual (Page 17)

17
Send
This message is never sent.
Receive
Receipt deselects RPN.
9.18 All Sound Off (78H)
Format
Send
This message is never sent.
Receive
Receipt stops all voices that are sounding.
9.19 Reset All Controllers (79H)
Format
Send
This message is sent when the keyboard channel is changed and when the recorder function is used.
Receive
Receipt initializes each performance controller.
10 Mode Message
10.1 All Notes Off (7BH)
Format
Send
This message is sent when the keyboard channel is changed and when a Music Library or recorder operation is performed.
Receive
Receipt of any of this message releases the currently sounding voice (same as releasing the keyboard key).
Message Format: BnH 78H 00H
n: MIDI Channel Number
Message Format: BnH 79H 00H
n: MIDI Channel Number
Message Format: BnH 7BH 00H
n: MIDI Channel Number