There are two types of RFID tags: those that are passive, have no power source, limited data storage capacity, are read only and have a limited read range, and those that are active, have their own power source, have a larger data-storage capacity, have a read/write capability and are readable from a greater distance.
Passive tags hold little actual data but are able to identify an item to a database where more comprehensive data is stored. For example, a conveyor-based sortation system can identify the item and interrogate the database to receive routing instructions.
Active tags have a higher capacity and can have their item’s status updated once a task has been completed. They have a shorter writing range than reading range and the internal power source is likely to burn out within 5 to 10 years.
The tracking of roll cages, pallets and returnable packaging such as totes, kegs, barrels and trays can be made simpler and cost effective through the use of RFID. The difficulty faced by proponents of RFID is that barcodes are so cheap to produce and remain an accurate and cost-effective method of identification. The cost of operating an RFID system will vary depending on the application, the size of installation, the frequencies used and the quantity of tags purchased. As take up increases, the costs will reduce. The following items are required to introduce an RFID application,
- RFID readers and tags
- Middleware
- Systems upgrades
- RF network within the warehouse
Current disadvantages of RFID include,
- reading issues when in close proximity to liquids and metal
- dead areas where signals are weak
- tags can be damaged by liquids, static discharges and magnetic surges
- Intermittent data capture, with the possibility of some tags not being read.