HP LD4210 42-inch LCD Digital Signage Display - Manual (Page 71)

[d][][Set ID][][OK][Data][x]
05. Volume Mute (Command: e)
To control On/Off of the Volume Mute.
Transmission
[k][e][][Set ID][][Data][Cr]
[Data] 0: Volume Mute On (Volume Off)
1: Volume Mute Off (Volume On)
Acknowledgement
[e][][Set ID][][OK][Data][x]
[Data] 0: Volume Mute On (Volume Off)
1: Volume Mute Off (Volume On)
06. Volume Control (Command: f)
To adjust Volume.
Transmission
[k][f][][Set ID][][Data][Cr]
[Data] Min: 00H to Max: 64H
(Hexadecimal code)
Acknowledgement
[f][][Set ID][][OK][Data][x]
[Data] Min: 00H to Max: 64H
ENWW Transmission/Receiving Protocol 63