>I am trying to set up a barcode system that links into an already existing accounting system in a point of sale, are there any problms that anyone has encountered doing this already?
>Also we are considering putting in touch screens, are there any problems with this from a coding point of view?
>cheers in advance
>Mark

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I had setup my Barcode system on my Sales System 2 years ago.

Everything problem will be solved if you buy a barcode printer and barcode scanner from shop, which got C programmer to make the menu-base program on barcode scanner.

What you need his scanner program to do:
Input:
set an Invoice#
read barcode(item#), qty

Output:
a text file, SDF with field:
Inv_no, Item, Qty

That's all. Remember, for C language, extra empty is \0,
i.e. Chr(0) in VFP

Okey, what will be the main problem on it.
User need to run Two application to finish the upload data.
1) Upload software (Barcode scanner -> Local harddisk)
2) Your sales system to import the text file.

Since data can't be duplicate nor dbl qty,
after user upload the data from scanner.
The data should deleted from barcode scanner!

Thus, if userA only do Step 1) and leave, and then userB come to do
1) and 2), userA data will be lost completely.

What I can do is remind again and again, Step 1) and 2) MUST do as if ONE process, else user take the responsibility on data loss.

On the other hand, how you print the barcode,
which type of code will be another view.
Find a shop who got programmer there, he will give full advise for you.

Code 93 is shortest on alphanumeric
2nd shortest is Code 128
Code 3 of 9 is longest.

EAN, UPC need register and they got a check digit.

If item# you use got Alphabet, Code 93 is best choice.