FINS Frames

Section 7-2

7-2 FINS Frames

The FINS communications service is carried out through the exchange of FINS command frames and their corresponding response frames. (There are also commands with no responses.)

Both command frames and response frames are comprised of a FINS header for storing transfer control information, a FINS command field for storing a command, and a FINS parameter/data field for storing command parameters and transmission/response data.

FINS command frames and FINS response frames are used with both FINS/

UDP and FINS/TCP.

FINS Command

Frame Format

FINS header

FINS command

FINS parameter/data

 

Size (bytes)

Contents

ICF

 

1

Displays frame information

RSV

 

1

Reserved by system.

 

 

 

GCT

 

1

Permissible number of gateways

DNA

 

1

Destination network address

DA1

 

1

Destination node address

DA2

 

1

Destination unit address

SNA

 

1

Source network address

SA1

 

1

Source node address

SA2

 

1

Source unit address

SID

 

1

Service ID

MRC

 

1

Main request code

SRC

 

1

Sub-request code

Parameter/

 

2000 max.

Command parameters and send data

data field

 

The data length depends on the MRC and SRC.

 

 

 

 

 

 

 

 

 

FINS Response Frame Format

FINS parameter/data field

FINS header

FINS command

MRES

SRES

Data

Size (bytes)

10

2

1

1

1998 max.

Contents

Same as in command frame.

Same as in command frame.

Main response code

Sub-response code

Response data

There are some frames in which the data length is 0.

FINS Header

 

 

 

 

 

 

 

 

 

Information

 

 

 

 

 

 

 

 

 

ICF (Information Control

 

 

 

 

 

 

 

 

 

Field)

Bit

7

6

5

4

3

2

1

0

 

 

 

1

 

0

0

0

0

0

 

Response Request Bit

(0: Response required; 1: Response not required)

Kind of data (0: command; 1: response)

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Omron CJ1W-ETN21 Fins Frames, Fins Command Frame Format, Fins Response Frame Format, Fins Header Information