Using Socket Services with CMND(490)

Section 6-8

Program Flow

Check socket status.

Is Bit 15 (Open Flag) in the socket status word for the socket being used OFF?

(Checks to see if the socket is open before com- munications and close processing.)

Check the Port Enabled Flag.

Is the Port Enabled Flag in A502 for communica- tions port ON?

Start UDP Open

OFF?

NO

YES

ON?

NO

YES

Error Evaluation

The specified UDP socket is already open.

The specified port is running network communications.

Execute FINS command (via CMND(490)) for Ethernet Unit.

Use the CMND(490) to send the UDP OPEN RE-

QUEST command (2701) to the Ethernet Unit.

Check response.

 

 

0000?

 

 

 

 

 

YES

Is the response code = 0000 (normal) for the

UDP OPEN REQUEST command?

 

 

 

 

 

Check Opening Flag status.

 

 

ON/OFF

 

 

 

 

 

 

NO

An error occurred. The Ethernet Unit did not receive the UDP OPEN REQUEST command.

(Socket status bit 00)

Wait until bit 00 in the socket status turns OFF (open complete).

Check results storage area response code.

Is response code = 0000?

0000?

NO

YES

UDP opened

An error occurred. The specified socket could not be opened.

6-8-3 Basic FINS Command Format

The basic format for FINS commands used for socket services is shown in the following diagram.

0

1

 

2

3

4

5

6

7

 

 

8

9 10 11 12

 

Byte order from the

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

beginning of the frame

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Command

 

 

 

 

 

Results storage area

 

Parameters

 

 

 

 

 

 

 

 

 

 

code

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Socket number

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Socket option

 

 

 

 

 

 

 

 

 

 

 

 

Command Code:

Specifies the process code requested from the socket.

Socket Option

For the TCP OPEN REQUEST (ACTIVE or PASSIVE) command, specifies whether or not the keep-alive function is to be used.

Socket Number

Specifies the socket number for the process, between 1 and 8.

Results Storage Area

Specifies the area to store the results of the requested process.

Parameters

Specifies the parameters defined for the command code.

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Omron CJ1W-ETN21 operation manual Basic Fins Command Format, Command Code, Socket Number, Results Storage Area, Parameters