Responses for commands and inquiries
●ACK message
Returned by the FCB camera when it receives a command. No ACK 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 ACK message is omitted, the socket number will contain 0.
| Reply Packet | Note | ||
Ack | X0 | 4Y FF | Y = socket number | |
Completion (commands) | X0 | 5Y | FF | Y = socket number |
Completion (Inquiries) | X0 | 5Y | ... FF | Y = socket number |
X = 9 to F: FCB camera address + 8
●Error message
When a command or 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, it is normal to 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 ACK 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 ACK message is not returned for these commands and inquiries, and only the completion message of socket number 0 is returned.
Command List
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 | Note |
Cancel | 8X 2Y FF | Y = socket number |
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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