FINS Frames | Section |
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. |
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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 | |
Parameter/ |
| 2000 max. | Command parameters and send data |
data field |
| The data length depends on the MRC and SRC. | |
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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
Response data
There are some frames in which the data length is 0.
FINS Header |
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Information |
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ICF (Information Control |
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Field) | Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
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| 1 |
| 0 | 0 | 0 | 0 | 0 |
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Response Request Bit
(0: Response required; 1: Response not required)
Kind of data (0: command; 1: response)
162