Barcode Reader and Sort Machine Control Strategy


This strategy was written to control a machine to physically sort 3 2/3" x 8 1/2" mail pieces based upon a 2D bar code that is printed on the piece.

The Process -
A mail piece is sent to a recipient with a 2D bar code that identifies the recipient. When the piece is returned to us it is scanned to PDF. The scanner feeds, at a rate of approximately 70 per minute, the piece onto a 40" in feed table, traveling at 27" per second. An eye detects the presence of the piece on the in feed table belt and starts the process. A Microscan bar code scanning camera is further down on the table and is triggered at a specific time to capture the 2D bar code image and send the data to the Snap Pac R1. The piece continues on and its position is changed from on its back to upright on its bottom edge to be presented to the sort bin section. The sort bin section, with a speed of 210" per second, consists of 16 sort pockets each with a solenoid gate that opens to divert the piece into its sort pocket. The Strategy gets the piece to a specific bin based upon a recipe populated table and the trigger of an Entry Eye as the piece enters the sort bin section.

One of four down timers checks to make sure a piece is where it needs to be before they expire (there are a maximum of 4 pieces moving in the machine at any point in time.

Run Rates and Run Speed are continually calculated .

A flag is set for the first PDF scan and every 100 scans so that PAC Display can bring up Reader from a command line so scan quality can be monitored.

The E_Stop_Monitor checks to see if a physical stop switch has been depressed or if a piece missed all 16 bins and went out the far end of the sort bin section.

I put each function into its own chart. I also labelled each flowchart step. I don’t need to remember what or how I did a function because every step tells me. The strategy is so stable I may not look at it for months at a time.

It is not that you will find anything remarkable in any specific chart, but the beauty lies in the coordination and functionality of the components. The credit goes to the PAC Control Basic platform. I am not an engineer or a programmer - I just knew what the functionality needed to be. I wrote one chart at a time verifying its functionality.

We were manually scanning pieces on a multi-function printer, and then manually sorting the pieces to send them to the individuals responsible for the territory the piece originated from. It was getting out of control with as many as 2000 pieces coming in for processing in a single day. Functions that took almost 30 hour a week of labor are now completed in less than 5 hours of labor per week. There were commercial options at a cost of as much as $160,000.00 plus yearly software maintenance contract costs. Our total cost, with our labor cost not considered because they were sunk costs, was less than $15,000.00.


the 2D bar code can be generated by barcode generator and we can use barcode scanner or read to scan in any angels automatically or manually in batch.


Thank you for your sharing! The most common barcode reader that I use is camera-based reader. Two-dimensional imaging scanners are the sixth and newest type of barcode reader. They use a camera and image processing techniques to [URL=“”]decode the barcode.