RFID Passive versus RFID Active

Automation professionals are usually concerned with the ecosystem of technologies the will best support the customer needs. In the case of RFID, because the technology is becoming more widespread, there is a lack of a systematic approach.

On one hand, automation can be as basic as the use of bar codes and scanners for the tracking of items. In this context, some consider RFID passive as the "new bar code" or the bar code on steroids endorsed by EPC just as UPC does for bar coding. The next phase we apply the technology pitched against the existing processes. This is the passive world. Then we have real life problems to consider with radio interference, metallic materials, Electromagnetic wave reflections, liquids, etc.

RFID active, on the other hand, is a more mature technology, nevertheless, because of cost, is not considered as a possible alternative for an application within the four walls. Therefore, RFID active is sandbox for vehicle tracking, cargo, or applications where the RFID tag will be exposed longer range of communication.

Then the question becomes: what is the approach for automation with RFID to automate processes when we have this two options?

Depending who you ask, some will try to use RFID passive because is cost effective in massive deployment. However, this approach , on my opinion, is shortsighted. Likewise when in an application where active RFID is chosen there are instances where clearly passive fits better.

On my opinion, the best approach is to take a balance view an consider RFID as a tool within the ecosystem of technologies to solve a problem or provide automation. RFID active should be chosen when there are data storage constraints and lighter reader infrastructure requirements. RFID passive should be chosen when there is the need of visibility at checkpoints such as portals, conveyors, and items that make up the pallet.

For instance, consider that once commissioned, an item with a RFID tag, at the end of the cycle, a nested load that accounts several of them as a group is the best approach for having the active RFID tag that is attached to the container. This enables the double assurance that:

1. 100% of the items have been accounted for and have RFID passive tags
2. The RFID active tag for the nested load has the master list, thus providing the 100% read rate in logical way rather than the physical way with RFID passive on portal
   

In summary, RFID technologies should fit the application and should be used as tools rather than platforms that are forced across a process. The advantage of RFID is the wireless data collection and as long as there are efficiencies, the ROI should be obvious besides the intangible value of the use of the technology.