How to detect when scanner start to scan , time out happened?

Public Function ScanStartMlt() As Integer
...
...
' start to scan
AddHandler _twSession.AcquirePage, AddressOf AcquirePageEvent
_twSession.Acquire(TwainUserInterfaceFlags.None)
RemoveHandler _twSession.AcquirePage, AddressOf AcquirePageEvent

...
...

End Function

My problem is :
When I call method ScanStartMlt,I shutdown my scanner(eg,powerdown), my procedure is stop(not exit).But no exception occured.My form couldn't give me any response.I can't do anything except force to exit my procedure.

How to resolve this problem.
For example ,when this problem has happened,I only want to wait 10 seconds.If I wait times > 10 seconds, give me a Messge from Form(But now I can't do anything).

My leadtool's version is LEADTOOLS 15.0J.

Waiting for you reply.
:)

Could you please test this using Twacker utility from the Twain Working Group? You can get it from here: http://www.twain.org/devfiles/twack.zip

To test, perform scanning from within Twacker for multiple pages, and immediately after scanning begins, turn of the scanner. Does Twacker respond or does it hang too?

Thanks,
Maen Badwan
LEADTOOLS Technical Support

Thank you for your reply.

I follow you description to do it.
Messagebox is popuped.

Title:DG_IMAGE/DAT_IMAGENATIVEXFER/MSG_GET
Content:TWRC_CANCEL

OK button clicked.

next OK button click.
c.gif is popuped

Ok button click,b.tif is popuped too.
Like this,messagebox is looped popup.
Always can't close all the messagebox except force to exit the TWacker.

When exactly do you get these messages?

To disable the Twacker messages, please do the following:
1. Open the Twack_32.exe.
2. Select the menu "File"\"Message Level"\"None"

Then use the following instructions to check the same issue using Twacker:

2. Select the menu "File"\"Select Source", and select your scanner twain driver.
3. Select the menu "File"\"Acquire", and scan multiple pages, and immediately after scanning begins, turn of the scanner. Does Twacker respond or does it hang too?

Please let me know how it goes.

Thanks,
Maen Badwan
LEADTOOLS Technical Support

Thank you for your reply.

I use your description to check the same issue using Twacker.

I wait about 10 minutes.
But the Twacker no respond and hang too.

My scannar is Kadok i260.

Since the scanner has the same problem in Twacker, then the problem lies in the Twain driver and you should contact your scanner manufacturer.

Thanks,
Maen Badwan
LEADTOOLS Technical Support