Scanning issues with Avision 186+

[yoavmmn]

I'm trying to scan documents using the following code:

import twain
from tkinter import *
from tkinter import messagebox
import traceback

root = Tk()
root.title('scan.py')

def scan():
    try:
        def counter():
            for i in range(1000):
                yield i

        count = counter()

        before = lambda file: 'C:/%s.png' % (next(count))

        srcManager = twain.SourceManager(parent_window=root)

        first_available = None

        for src in srcManager.source_list:
            print(src)
            try:
                first_available = srcManager.open_source(product_name=src)
            except:
                continue

        result = first_available.acquire_file(before=before,
                                    after=lambda file: print(file),
                                    show_ui=True,
                                    )
    except:
        messagebox.showerror("Error", traceback.format_exc())
        sys.exit(1)
    else:
        sys.exit(0 if result else 1)

root.after(1, scan)
root.mainloop()

This code produce the following error using Avision 186+, but works fine on HP LaserJet M426FDN and I need to support both scanners.

Traceback (most recent call last):
  File "C:/Users/Web/Desktop/pytwain-master/demo/scan.py", line 45, in scan
    show_ui=True,
  File "C:\Users\Web\AppData\Local\Programs\Python\Python37-32\lib\site-packages\twain.py", line 2054, in acquire_file
    self._acquire(callback, show_ui, modal)
  File "C:\Users\Web\AppData\Local\Programs\Python\Python37-32\lib\site-packages\twain.py", line 1856, in _acquire
    self._modal_loop(callback_lolevel)
  File "C:\Users\Web\AppData\Local\Programs\Python\Python37-32\lib\site-packages\twain.py", line 1837, in _modal_loop
    callback(event)
  File "C:\Users\Web\AppData\Local\Programs\Python\Python37-32\lib\site-packages\twain.py", line 1852, in callback_lolevel
    more = callback()
  File "C:\Users\Web\AppData\Local\Programs\Python\Python37-32\lib\site-packages\twain.py", line 2042, in callback
    raise excDSTransferCancelled
twain.excDSTransferCancelled

Any ideas?

[denisenkom]

This library is just a wrapper around TWAIN library. Take a look at TWAIN specification for more troubleshooting ideas: http://www.twain.org/wp-content/uploads/2017/03/TWAIN-2.4-Specification.pdf

Let me know if the problem is with the wrapper.