FINS/TCP Method | Section |
•When routing tables are used for one or more other nodes on the same network.
It is not necessary to set routing tables if one Communications Unit is mounted to the PLC and the nodes are connected as one network.
For details on setting routing tables, refer to the section on creating routing tables in Section 6 FINS Communications in the Operation Manual, Construc- tion of Networks.
7-4-2 FINS/TCP Mode Specifications
FINS/TCP Headers
FINS NODE ADDRESS DATA SEND (CLIENT TO SERVER) Command
When this command is executed, the client node stores its own FINS node address in the client node address and notifies the server. This command is sent after the TCP connection is established (ESTABLISH).
When specifying automatically allocated FINS node addresses, specify 00000000 hexadecimal for the client node address.
After a connection has been established as a FINS/TCP client or server, do not send this command again. Otherwise, the error code (00000003 hexadec- imal: The command is not supported) will be received in the FINS FRAME SEND ERROR NOTIFICATION command and the connection will be termi- nated.
FINS/TCP header
Header
Length
Command
Error code
Client node address
Size (bytes)
4
4
4
4
4
FINS NODE ADDRESS DATA SEND (SERVER TO CLIENT) Command
The details of the above frame are shown in the following table.
Item | Contents (hexadecimal) | Remarks |
|
|
|
Header | 46494E53 | ASCII code: ‘FINS’ |
|
|
|
Length | 0000000C | 12 bytes: Length of data from |
|
| command onwards. |
|
|
|
Command | 00000000 |
|
|
|
|
Error code | 00000000 | Not used, so does not require |
|
| checking by server. |
|
|
|
Client node address | 00000000 to 000000FE | 0 to 254 |
(FINS node address |
| Note: Client FINS node |
| addresses are automatically | |
of FINS/TCP client) |
| |
| obtained when set to 0. | |
|
|
When this command is executed, the server node notifies the client of its own FINS node address. This command is sent after the server has received the FINS NODE ADDRESS DATA SEND (CLIENT TO SERVER) command. The FINS NODE ADDRESS DATA SEND (CLIENT TO SERVER) command received by the server is decoded and if any errors are detected, the error details are sent by adding to the Error Code in the command, and then the connection is closed.
When this command is received by the client node, the TCP/IP port must be closed quickly, unless the contents of the Error Code are 00000000 hexadeci- mal (normal).
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