Chapter 1. Application Development; Application Control - Hitachi HT-4139-28 Developer's Manual

1 A p p l i c a t i o n D e v e l o p m e n t

Chapter 1. Application Development

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When you develop an application program that controls a TWAIN scanner, it is necessary to understand
the TWAIN standard (TWAIN Release v1.9) fully.

1.1 Application Control

Followings should be prepared to start and control a session through the TWAIN application.
This TWAIN driver complies the TWAIN standard and consists of 7 protocol states.
State 1 - Pre-Session
State 2 - Source Manager Loaded
State 3 - Source Manager Open
State 4 - Source Open
State 5 - Source Enabled
State 6 - Transfer is Ready
State 7 - Transferring
Proceed application as follows.
Load the Source Manager and Get the DSM_Entry (State 1 to 2)
 O pen the Source Manager (State 2 to 3)
 S elect the Source (during State 3)
 O pen the Source (State 3 to 4)
 N egotiate Capabilities with the Source (during State 4)
 R equest the Acquisition of Data from the Source (State 4 to 5)
 R ecognize that the Data Transfer is Ready (State 5 to 6)
 S tart and Perform the Transfer (State 6 to 7)
 C onclude the Transfer (State 7 to 6 to 5)
 D isconnect the TWAIN Session (State 5 to 1 in sequence)
Points to notice on control will be described from the next chapter.
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