Handshake mechanism between host and device to initiate scan operation and coordinate the transfer of scanned image data to the host. This object serves both as an indicator of scan upload activity as well as a trigger for the host to alter scan upload progress. The handshake is on a per page basis to allow greater host control. eScanUploadIdle - indicates the scan upload activity is not occurring. Host setting this object to eScanUploadIdle from eScanUploadActive will cause the scan upload activity to be prematurely terminated. Host may set object to this state at any time. Device sets object to this state only upon initial power up but will otherwise never set to this state of its own accord. eScanUploadStart - indicates host requesting to commence a scan to host operation. Host may set object to this state from eScanUploadIdle or eScanUploadNewPage. Device will not set object to this state of its own accord. eScanUploadActive - indicates scan upload activity is occurring. The device sets object to this state to indicate host may commence receiving scanned image data. During this state, the device will be writing scanned image data to the I/O channel. eScanUploadAborted - indicates the scanning and scan upload activity has terminated in error state. This value is set by the device. This state is not settable by the host. The host should transition this state to eScanUploadIdle. eScanUploadDone - indicates the device is signaling successful completion of scan upload activity and there are no more document pages in the scanner/ADF. The application should set this object to eScanUploadIdle. eScanUploadNewPage - indicates the device is signaling successful completion of scan upload activity for the current page and there remains at least one page in the scanner/ADF available for scanning. Host may choose to begin scan upload cycle by setting object to eScanUploadStart or end the cycle by setting object to eScanUploadIdle. Additional information: eScanUploadNewPage - indicates the device is signaling successful completion of scan upload activity for the current page. There may be a page in the device or not. The device will wait to prefeed another page until the application sets the object to eScanUploadStart. This was to fix a bug on HP LaserJet 1100 that a prefed page would cause a jam if the application set the object to eScanUploadIdle. The application could not create another scan job until the prefed page was removed. Host may choose to begin scan upload cycle by setting object to eScanUploadStart or end the cycle by setting object to eScanUploadIdle.