Fujitsu M3097DG Oem Manual page 174

Scanner Interface
A.4.14 SCAN
The normal SCAN sequence for the scanner is as follows:
Step
1 Bus Free
2 (Arbitration)
3 Selection
4 (Message Out)
5 Command
6 Data Out
7 Status
8 Message In
9 Bus Free
(1) SCAN command: Command phase (Initiator to Target)
The SCAN command defines reading method for the scanner.
The command descriptor block (CDB) is as follows:
7
Byte 0
1
Logical unit number
2
3
4
5
•
Transfer length: Byte 4
The transfer length specifies the number of bytes of window data sent during the DATA OUT
phase. A 0 means that no data is transferred. This is not an error.
Appendix A-104
Bus phase Initiator operation
Checks Bus Free
Acquires the right to
use the bus
Selects the target
Selects the logical
device
Specifies SCAN
(CDB)
Specifies the window
ID
6 5 4
Operation code X'1B'
Allocation length
Control byte
← →
3 2
(Reserved)
(Reserved)
Target operation
→
Drives the BSY signal
→
→
Specifies reading
→
←
Reports the GOOD status
←
Reports message
(Command complete)
Releases the BSY signal
1 0