FOCUS Enhancements 3.2 - Manual (Page 165)

External Control Commands
151
Multi-Track Jump Reverse (JR)
Command:
Jumps backward in the current MPEG file or playlist by the
amount specified in the <address> argument.
Format:
<address>JR<CR>
Response:
R<CR>
Explanation:
The Jump Reverse command is similar to the search command
accept that the address argument is interpreted relative to the
current file and playlist position and the new position is always
before the current position. In the event that a Jump Reverse
command is received with an out of range address value (i.e. –
chapter number greater than the current file in the playlist) the
Jump Reverse command will not be processed and the error code
“E12” will be returned.
Examples:
0@CH1JR
Jumps to the head of the current file and then transitions to still
mode. The only condition under which this command could
generate an error code would be if video was stopped or if no
playlist was loaded.
0@CH3JR
Jumps to the head of the second file before the currently playing
file and then transitions to still mode. If for example file 4 is
currently playing, this command would advance to the head of file
2. If the currently playing file is less than the third file in the
playlist error code E12 is returned and no change is made.