Filter
Top Products
- 7
2. USI.DLL – Unitech Scanner Interface DLL
Note : For PA500 programming, it need to dynamically load DLL for using Unitech built-in DLL (Unitech
will not provide *.H and *.LIB for compiler for mobile 5.0 OS), please refer to Chapter 7 for
programming guide.
2.1. Register the application to the USI DLL
Function Description: Register the application to the USI DLL, so that the DLL can communicate with
the application. It will also open and initial scanner port (COM2, for example) and set the scanner to
the working mode. The application should call USI_Unregister to unregister from the DLL after done
with the scanner.
Function call:
BOOL USI_Register(HWND hwnd, UINT msgID);
Parameter: (input)
hwnd: Handle of the window to which USI DLL will send messages to report all
activities, including error messages, scan data ready, etc.
msgID: Specifies the message to be posted. DLL will post messages by calling:
PostMessage(hwnd, msgID, msg, param).
The window procedure will receive custom message about msgID and wParam parameter
can be one of the followings:
SM_ERROR_SYS: Indicates a system error, which is caused by a call to the system
function. Param contains the error code from GetLastEror().
SM_ERROR Indicates an error. Param contains the cause of error, which can
be on of followings:
SERR_INVALID_HWND: Invalid window handle.
SERR_INVALID_MSGID: msgID cannot be 0.
SERR_OPEN_SCANNER: Open or initial scanner port failed.
SERR_CHECKSUM: Checksum error in received
packet.
SERR_DATALOST: New scan data is lost because data buffer is
not empty.
SERR_BUFFEROVERFLOW:Data buffer overflow. The default size is 4K bytes.
SM_REPLY Indicates received a reply. All the responses from the scanner
except the scan data will be notified by this message.
SM_DATAREADY Indicates that scan data is successfully decoded and ready to
retrieve.
SM_ACK Indicates received a ACK.
SM_NAK Indicates received a NAK.
SM_NOREAD Indicates received a No-Read packet.
Note: Scanner port settings are defined in registry as described below:
[HKEY_LOCAL_MACHINE\SOFTWARE\Unitech America Inc.\Scanner\Settings]
"COMPORT"="COM2:"
"BAUDRATE"="38400"
"STOPBITS"="1"
"PARITY"="None"