User`s manual
Alcorn McBride Digital Video Machine HD User’s Manual Rev 1.0
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Command Protocol
The Serial, Ethernet, Playlist, Scheduler, and GPS control interfaces use the Pioneer
Alcorn McBride Enhanced protocol. This protocol implements nearly all of the Pioneer
Laser Disc player command set, but adds commands to access advanced features of
the DVMHD as well. This section discusses the most commonly used commands in
detail.
The protocol is ASCII-based. Upper or lower case characters can be used
interchangeably. All commands and responses are terminated with the Carriage
Return character. This character is represented by the hexadecimal value of
0x0D.
Commands sent to
individual units
using the address
operator (@) will
receive a message
response, but a
wildcard message
will not.
Addressing Commands
Although it is not necessary, any command can be preceded by <ID>@ where <ID>
is the ASCII representation of the unit’s Device ID (‘0’-‘126’). This allows commands
to be sent to individual units in a control line of multiple units. The address ‘127’ and
‘*’ act as wildcard ID’s; a command sent using ‘127’ or ‘*’ as the ID will cause all
units in the control line to execute the command. The Device ID can be assigned at
any time using the Set Device ID command listed in the later in this section.
Playback Commands
Search File
Description: This command causes the DVMHD to search the specified A/V clip or
Playlist. If a video clip is specified, the first frame of video is displayed
on the video output when the search is complete. After a successful
search, a Play will cause the specified file to play immediately (meaning
less than 1 frame of latency) from the beginning.
Command Bytes: nnnnnSE or “<filename>”SE
Parameters: nnnnn is the ASCII file number between 0-99999.
<filename> is an ASCII file name surrounded by quotation marks.
Message Response: R
Comments: This is similar to the “Search to Address” command in chapter
addressing mode used in Pioneer Laser Disc protocol. The maximum
file number is 99999.
Examples: Search file 215: 215SE
Search file 4: 4SE or “vid00004.mpg”SE
Search file alcorn.mpg: “alcorn.mpg”SE