CInScan02.py 文件源码

def start_scan(self):
        rate = 390
        total_count = 100

        # Allocate a buffer for the scan
        memhandle = ul.win_buf_alloc_32(total_count)

        # Check if the buffer was successfully allocated
        if not memhandle:
            messagebox.showerror("Error", "Failed to allocate memory")
            self.start_button["state"] = tk.NORMAL
            return

        try:
            # Configure the counter
            ul.c_config_scan(
                self.board_num, self.chan_num, CounterMode.DECREMENT_ON,
                CounterDebounceTime.DEBOUNCE_NONE, 0,
                CounterEdgeDetection.FALLING_EDGE,
                CounterTickSize.TICK20PT83ns, 1)

            # Run the scan
            ul.c_in_scan(
                self.board_num, self.chan_num, self.chan_num, total_count,
                rate, memhandle, 0)

            # Convert the memhandle to a ctypes array
            # Note: the ctypes array will only be valid until win_buf_free
            # is called.
            # A copy of the buffer can be created using win_buf_to_array_32
            # before the memory is freed. The copy can be used at any time.
            array = self.memhandle_as_ctypes_array_32(memhandle)

            # Display the values
            self.display_values(array, total_count)
        except ULError as e:
            self.show_ul_error(e)
        finally:
            # Free the allocated memory
            ul.win_buf_free(memhandle)
            self.start_button["state"] = tk.NORMAL