4 External Computer Control — Level III
This chapter describes the computer control protocol and specific commands used
for Level III control of the LD-V8000. To attach a computer to the LD-V8000 via the
player’s RS-232 port, refer to
Appendix C
,
Interface Cable Specifications
. See
Section 2.4 On-Screen Function Switches
to select Input Device, Baud Rate, etc.
4.1 Command and Status
In the LD-V8000 external computer control protocol, the computer transmits a
command, and the player returns the execution completion status.
ASCII character codes are used for the actual commands and status responses.
The command mnemonic is expressed as two ASCII characters.
In most cases, there is no distinction between the use of uppercase or lowercase
letters, and the use of uppercase letters is recommended.
Arguments may be set to specify the frame number, speed or other values for a
command. The argument is always placed before the command. The command is
also used as the terminator of the argument. In the simplest protocol, the player
immediately executes one command as soon as the terminator of the command
line, a <CR> (carriage return), is received.
Example:
1000SE<CR> : Search to frame 1000.
The player has a command buffer that allows multiple commands to be sent from
the external controller in the same command string.
Example:
1000SE 2000PL <CR> : Search to frame 1000, then play to frame 2000.
In this example, when the <CR> is received, commands are executed sequentially
from the first command of the buffer.
LD-V8000 Level I & III • Chapter Four
5) “Play to Frame 2000”<CR>
->->->
6) Play Execution
4.) R (received) <CR>
<-<-<-
3) “Completion”
8.) R (received) <CR>
<-<-<-
7) “Completion”
Computer
Laser Videodisc Player
1) “Search to Frame 1000”<CR> ->->->-
2) Search Execution
LD-V8000 Level I & III User’s Manual
TP 113 v. 2.1 • 2/93
4-1
Figure 4-A
