Such as what is a prefix and suffix, why are they used.
Got to install a scanner via a basic module in a 5/04, so the barcode can be displayed on a panelview.
Any help appreciated
Cheers
Graeme
Full Version: Barcodes
Can anyone tell me any web sites or manuals that will give me an idiots guide to barcodes and scanners.
Such as what is a prefix and suffix, why are they used.
Got to install a scanner via a basic module in a 5/04, so the barcode can be displayed on a panelview.
Any help appreciated
Cheers
Graeme
Such as what is a prefix and suffix, why are they used.
Got to install a scanner via a basic module in a 5/04, so the barcode can be displayed on a panelview.
Any help appreciated
Cheers
Graeme
I got in my hands a small book made by A-B that I think is pretty good.
Called:
Bar Code Basics
Publication: 2755-921
I don't know if you can find that any where free on the web or not. I also assume they have a newer version of this book somewhere, as this one is rather old.
The reason I use prefixes is so you can tell which barcode reader it came from and suffix so you know when the string has ended.
Example: If I have four bar code readers that are wired RS-485 into a MUX (mulitplexor), then I connect my MUX via RS-232 direct to my serial port on my front port of my 5/03, I need to know what strings are coming from what bar code. So I setup a prefix different from each of the four bar code readers.
string #1 = /1/ ABCD123 /n/ came from bar code #1
string #2 = /2/ ABCD123 /n/ came from bar code #2
string #3 = /3/ ABCD123 /n/ came from bar code #3
string #4 = /4/ ABCD123 /n/ came from bar code #4
If you are monitoring your buffer on your 5/03 you might get this for a string in one scan:
/2/ ABCD123 /n/ /4/ ABCD123 /n/ /1/ ABCD123 /n/
So you have to decode that into useful information, by looking for a prefix, and then your "DATA" and know when your data ends by looking for a suffix.
The readers I like to use are DataLogic RASTER scanner 500 lines per second, and DataLogic's MUX32 module, and just a plain old serial port on the front of the SLC 5/03. I don't like to fight the basic module, and I can write all my code in ladder logic for my bar code readers.
Fight the basic module, meaning I need more practice on using it before I say I like it.
In the Datalogic setup software, you can define anything you want for a prefix and suffix strings. I am pretty sure you can do that in any reader also.
Hope that helps.
Called:
Bar Code Basics
Publication: 2755-921
I don't know if you can find that any where free on the web or not. I also assume they have a newer version of this book somewhere, as this one is rather old.
The reason I use prefixes is so you can tell which barcode reader it came from and suffix so you know when the string has ended.
Example: If I have four bar code readers that are wired RS-485 into a MUX (mulitplexor), then I connect my MUX via RS-232 direct to my serial port on my front port of my 5/03, I need to know what strings are coming from what bar code. So I setup a prefix different from each of the four bar code readers.
string #1 = /1/ ABCD123 /n/ came from bar code #1
string #2 = /2/ ABCD123 /n/ came from bar code #2
string #3 = /3/ ABCD123 /n/ came from bar code #3
string #4 = /4/ ABCD123 /n/ came from bar code #4
If you are monitoring your buffer on your 5/03 you might get this for a string in one scan:
/2/ ABCD123 /n/ /4/ ABCD123 /n/ /1/ ABCD123 /n/
So you have to decode that into useful information, by looking for a prefix, and then your "DATA" and know when your data ends by looking for a suffix.
The readers I like to use are DataLogic RASTER scanner 500 lines per second, and DataLogic's MUX32 module, and just a plain old serial port on the front of the SLC 5/03. I don't like to fight the basic module, and I can write all my code in ladder logic for my bar code readers.
Fight the basic module, meaning I need more practice on using it before I say I like it.
In the Datalogic setup software, you can define anything you want for a prefix and suffix strings. I am pretty sure you can do that in any reader also.
Hope that helps.
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