- 5
1. Introduction
1.1 How to download data from scanner
The major difference between the PA500 and a standard HPC/PalmPC is barcode input
capability. The WinCE Reference Manual contains no information regarding barcode input.
This section will introduce the programming structure of the barcode sub-system and the
programming utility library for the PA500. Inside the PA500 there is an advanced decoding
chip to control SE900 laser engine and to handle barcode decoding. Below is system
diagram for the PA500 barcode:
According to the above diagram, the PA500 communicates with Decoder Chip by mean of
serial port COM2. Its communication parameter is fixed on 38400,N,8.1. Normally, the
Decoder Chip is in sleep mode when COM2 is not activated. When COM2 is activated, the
Decoder Chip will start working, and it will decode the barcode “signal” from the laser engine
when the trigger key is pressed. After decoding, barcode data and its symbology type will
be sent directly to PA500.
Many programmers find it difficult to control the Decoder Chip via programming language
alone, especially if they are not familiar with barcode and serial port controls. Because of
this, Unitech provides the following utility library and program for the user or application
programmer to control the Decoder Chip:
1. Application program “Scan2Key.exe” is a useful application program that can read
input data from the laser scanner and then directly input the data into PA500’s
keyboard buffer. “Scan2Key.exe” makes barcode data input simple, and can be
especially valuable to those programmers not familiar with COM port programming.
User program simply reads the barcode data from the keyboard. For barcode
symbologies setting, you can run
Scanner Setting
from
Control Panel
to define all of
supporting symbologies and delimiter.
2. Utility library:
For programming control, PA500 provides USI.DLL to let user control scanner input,
symbologies setting and profile controlling. Please refer to 2 for detail API lists.
USI.DLL is Unitech’s new scanner function library on PA500. For backward compatible
issue, Unitech still provide Scanner3.DLL and ScanKey3.DLL for existing
PT930/PT930SA user to port their software into PA500, but several APIs on
Scanner3.DLL and ScanKey3.DLL have already been removed on PA500. User can
refer to 0and 5 for detail supporting API.
CPU
COM2
Advanced
Decoder
Chip
SE950
Laser
Engine
