Bar scanner interface with Compactlogix L45

[kiran]

Hi all,


I need to read bar code scanner and process the info. in compactlogics PLC. Our customer is using a Honeywell 3800g barcode reader. The process is,


The operator scans the Work order using the scanner with Ascii data output format.
I need to transfer this information to the PLC and lookup part number and associated process parameters in the PLC. I will be setting up a recipe table for various parts for this.

I have not interfaced /programmed a barcode reader in the past. Could some one give some tips on diff. ways of achieving this and what are the hardware/s/w requirements. I will be using a touch screen on Ethernet on this cell.



Thanks,

 

[Ken Roach]

Start by reading up on the ASCII port instructions (clearing buffers, checking data length, reading data into STRINGs) and the ASCII string manipulation instructions (extracting values, concatenating strings, comparing strings, etc) in the RSLogix 5000 General Instruction Set Reference.

Read up also on the STRING data type in RSLogix 5000. There are some sensible differences in the STRING data type (length, character storage) and the custom String data types in RSLogix 5000 as compared to the way that ASCII and Strings were done in the PLC5/SLC/MicroLogix that you might be familiar with.

The physical interface will almost certainly be RS-232, using ASCII protocol. Look up the specifics from the barcode scanner.

Barcode scanner logic is often one-way, with the controller just continuously checking the serial port for data. Some scanners also allow configuration or command codes to be sent to them, like to turn the laser on and off or to change the decode type.

Find and post a link to the ASCII specifics for this barcode scanner and folks can help you get the CompactLogix serial port set up right, and help you start reading data into the controller.