Pioneer Industrial DVD Player DVD-V7400 - Manual (Page 19)

Command Structure
4.5 Error Message
An error message consists of an E followed by a two-character error code.
Example: EN
1
N
2
<CR>
The error message occurs when the given command cannot be processed.
4.6 Request Status Return
In response to a single request command, the status returns as a line of letters
terminated by <CR>.
If multiple commands are sent within the same String, the player returns a
separate status value upon completion of each command. A status value is a
character string with a <CR> termination code.
Example: ?C?F<CR> ⇒ 02<CR>
10260<CR>
When the command is at the end of the command string, the R within the
completion message is omitted.
Example: ST?F<CR> ⇒ 23005<CR> (completion omitted)
Example: ?FST<CR>
⇒ 23005<CR>R<CR> (not omitted)
4.7 Timing
A player needs a brief period after receiving a command before returning a
Status Value or “R <CR>”. It is defined as follows:
T1 represents the time between the termination of the command string
<CR> received and the beginning of the command execution. It is
approximately 35ms maximum.
T2 represents the time for executing the command, depending upon the
command type and the player’s condition. In case of a status request
command such as “?F”, T2 requires less than 1ms.
T3 represents the time that is needed for transferring data (TxD) per byte.
It requires a maximum of 4ms per byte. In case of the return data for “?F”
request, a player is supposed to be back 8 bytes data, that is composed
of 7 digit Frame number and “<CR>”. In this case the transfer time of
each byte is not exactly the same with 4ms, it takes usually around 10ms
for transferring 8 bytes data total, and it is supposed to take less than
16ms.
- 12