A.4 Commands

A.4.10 SEND command

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

Step

Bus phase

Initiator operation

← →

Target operation

 

 

 

 

 

1

BUS FREE

Verifies bus free

 

 

 

 

 

 

 

2

ARBITRATION

Obtains bus-usage

 

 

 

 

right

 

 

 

 

 

 

 

3

SELECTION

Selects target

 

 

 

 

 

 

 

 

 

 

Drives BSY signal

 

 

 

 

 

4

MESSAGE OUT

Selects logical unit

 

 

 

 

 

 

5

COMMAND

Specifies SEND

 

 

 

(CDB)

 

 

 

 

 

 

 

6

DATA OUT

 

Transfer data

 

 

 

 

 

7

STATUS

 

Reports GOOD status

 

 

 

 

 

8

MESSAGE IN

 

Reports Command Complete

 

 

 

 

 

 

 

 

 

Releases BSY signal

 

 

 

 

 

9

BUS FREE

 

 

 

 

 

 

 

 

Appendix A-81