BizTalk RFID Better Duplicate Tag Eliminator

Project Description
The Better Duplicate Tage Eliminator is a BizTalk RFID Event Handler that eliminates duplicate RFID tag reads.

Project Details

This project began after experiencing problems with the Microsoft Provided Duplicat Tag Elimination Event Handler provided as part of BizTalk RFID (http://msdn.microsoft.com/en-us/biztalk/bb608378.aspx). This Code Sample is provided as an example of writing an event handler. It is an excellent example of how to implement an event handler. However, it's implementation of duplicate tag reads is flawed. The following issues are present in the code:

• Duplicate elimination is based on a single day's clock. Tag Reads will be eliminated if they occur on subsequent days at a time before the original read (ie. Tag 123 read at 2PM on Day 1 will be suppressed on day 2 if it is seen before 2PM).
• The internal cache of tag reads and time stamps is never cleared. This event handler's in-memory size will continue to grow as it runs. The process it is a member of has to be recycled to have it's memory reclaimed.
• The logging messages do not hex encode the tags reads. This makes reading the logs for troubleshooting purposes very difficult.

This project is not intended as a crticism of the Microsoft code sample. It's purpose is to make a properly functioning duplicate tag eliminator available to the community. The Microsoft code sample is commonly used in tutorials and examples. This has led to it showing up in production environments where users are unaware of its flaws. This is precisely what this project hopes to eliminate.

Event Handler Properties



DuplicateInterval(in secs) - The number of seconds that represent the time span in which duplicate tag reads will be supressed.
EnableLogging - If set to True, verbose logging will be active. If set to False, logging will only be on for error level messages.
Relative Time Out - If set to False, duplicates will be suppressed in an absolute time span from the first time a tag is read. If set to True, duplicates will be suppressed relative to the last time a tag was seen.