Responses for commands and inquiries

●ACK message

Returned by the FCB-EX780S/SP when it receives a command. No ACK message is returned for inquiries.

●Completion message

Returned by the FCB-EX780S/SP 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-EX780S/SP 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-EX780S/SP address + 8, Y = socket number

Socket number

When command messages are sent to the FCB- EX780S/SP, 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-EX780S/SP has two buffers (memories) for commands, so that up to two commands including the commands currently being executed can be received. When the FCB-EX780S/SP 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-EX780S/SP 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 IF_Clear 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-EX780S/SP 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.

20