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
1
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.
1-1