Sony FCB-ER8550 Technical Manual page 31

Responses for commands and inquiries
 Acknowledge message
Returned by the FCB camera when it receives a
command. No Acknowledge message is returned for
inquiries.
 Completion message
Returned by the FCB camera when execution of
commands or inquiries is completed. In the case of
inquiry commands, it will contain reply data for the
inquiry after the 3rd byte of the packet. If the
Acknowledge message is omitted, the socket number
will contain 0.
Reply Packete
Acknowledge X0 4Y FF
Completion (Commands) X0 5Y FF
Completion (Inquiries) X0 5Y ... FF
X = 9 to F: FCB camera address + 8, Y = socket number
 Error message
When a command could not be executed or failed,
an error message is returned instead of the
Acknowledge message. After an Acknowledge
message, an error message may be returned if the
process of some command (zoom, etc.) has not been
completed.
When a inquiry command could not be executed or
failed, an error message is returned instead of the
completion message.
Error Packet Description
X0 6Y 01 FF Message length error (>14 bytes)
X0 6Y 02 FF Syntax Error
X0 6Y 03 FF Command buffer full
X0 6Y 04 FF Command cancelled
X0 6Y 05 FF No socket (to be cancelled)
X0 6Y 41 FF Command not executable
X = 9 to F: FCB camera address + 8, Y = socket number
Socket number
When command messages are sent to the FCB camera,
send the next command message after waiting for the
completion message or error message to return.
However to deal with advanced uses, the FCB camera
has two buffers (memories) for commands, so that up
to two commands including the commands currently
being executed can be received. When the FCB camera
receives commands, it notifies the sender which
command buffer was used using the socket number of
the Acknowledge message. As the completion message
or error message also has a socket number, it indicates
which command has ended. Even when two command
buffers are being used at any one time, an FCB camera
management command and some inquiry messages
can be executed.
The Acknowledge message is not returned for these
commands and inquiries, and only the completion
message of socket number 0 is returned.
Command execution cancel
To cancel a command which has already been sent,
send the Cancel command as the next command. To
cancel one of any two commands which have been
sent, use the cancel message.
Cancel Packet
Cancel 8X 2Y FF
X = 1 to 7: FCB camera address, Y = socket number
An error message will be returned for this command,
but this is not a fault. It indicates that the command has
been canceled.
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