Explanation:
When this command is received, the scanner starts a scanning operation (image reading) for the specified reading area, and sends the image data to the host computer as data blocks.
Image data of one line (one main scan of data) is sent as a data block, and a data block is sent for each sub scan reading length.
When the computer receives a data block, it should send an ACK code to indicate that it has accepted the data block and to prompt the scanner to send the next data block. If the computer fails to send an ACK code within 30 seconds after it receives a data block, an interface error occurs in the scanner.
When the computer receives the last data block (the last line of the image), it should not send the ACK code. If it sends an ACK code after the last data block, a command error occurs in the scanner.
Note:
❏After accepting the last data block, the host computer should not send an ACK code to the scanner.
❏The area end flag of the status byte is set to 1 in the last data block.
Aborting a scanning operation
Scanning can be aborted by sending a CAN code in place of an ACK code after the computer receives a data block.
When the CAN code is received, the scanner returns an ACK code in response, then terminates the remaining scanning operation.