A Barcode Reader to PC Connection

After buying a simple CCD hand held bar code reader, I soon found out how little

information there is available about the actual connections to a PC.

I have a Matsushita 84TMD2CA  reader. It has a DB9 plug with pin 5 removed, the fact

that pin 5 was removed led to to believe it was not a simple case of plugging it into my PC COMx port.

Investigating the unit I came up with this connection and tested it using Windows HyperTerm.

BarcodeConnection.jpg (10125 bytes)

I connected the RTS/CTS lines on the reader side so that the reader would

work without hardware handshaking.

Here is the practical implementation of the connection schematic.

BarcodeAdapter.jpg (33850 bytes)

Testing.

Start Hyperterm and setup for Direct Connection using COM1 or COM2 or whatever COM port you plan to use.

Setting are as follows:

4800 Baud, 7 bit, Even Parity, 1 stop bit.

I tested this reader using Code 128.

Here is a link to a site where you can print examples for testing.

http://www.idautomation.com/java/AppletDemo.html

This is also a good place to pickup Barcode Fonts and related items.

My original plans for this barcode reader was to use it for a totally different application.

However if I were to use it as a simple barcode reader to enter data into a program it would require

a program that is called "A Wedge" strange name !

A wedge program simply monitors the barcode reader and each time a valid barcode is read, it

generates keystrokes and enters the data wherever the cursor happens to be in a program. That is a simple

description of what a wedge program does.  May be when I get tiem I'll write a Wedge program for my Jornada Pocket PC using Windows CE .

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ęCopyright 2005 Hans Wedemeyer, Houston, Texas, U.S.A. All Rights Reserved.