4.4.9OBJECT POSITION command

The following table shows the normal sequence of the OBJECT POSITION command when used with this scanner.

Step

Bus phase

Initiator operation

¨ Æ

Target operation

 

 

 

 

 

1

BUS FREE

Verifies bus free

 

 

 

 

 

 

 

2

ARBITRATION

Obtains bus>usage

 

 

 

 

right

 

 

 

 

 

 

 

3

SELECTION

Selects target

Æ

 

 

 

 

 

 

 

 

 

 

Drives BSY signal

 

 

 

 

 

4

MESSAGE OUT

Selects logical unit

Æ

 

 

 

 

 

 

5

COMMAND

Specifies OBJECT

Æ

Loads/unloads paper (ADF)

 

 

POSITION (CDB)

 

 

 

 

 

 

 

6

STATUS

 

¨

Reports GOOD status

 

 

 

 

 

7

MESSAGE IN

 

¨

Reports message (Command

 

 

 

 

Complete)

 

 

 

 

 

 

 

 

 

Releases BSY signal

 

 

 

 

 

8

BUS FREE

 

 

 

 

 

 

 

 

(1)OBJECT POSITION command: COMMAND phase (initiator Æ target)

The OBJECT POSITION command controls the sheets in the ADF. When the ADF is used for reading, document sheets are loaded with this command before the READ command is issued.

The CDB of this command is shown in the following illustration.

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