Active RFID: greater efficiency in warehouses with perishable products

Perishable products introduce greater complexities into the logistics and handling since the order in which they are stored and dispatched is crucial. Besides appropriate optimisation of the warehouse and the use of specific metal racking such as dynamic pallet racking, with a FIFO flow, the traceability along the supply chain can prevent large economic losses because of products which have passed their sell-by date or deteriorated.

Passive RFID, the RFID that we all know

The name RFID, initials in English for Radio Frequency Identification, is a system which consists of tags that can be attached to any product. Each RFID tag includes a small chip that provides information about the product through radio-frequency and thus uniquely identifies it.

The commonest RFID is the passive RFID, which is the one that we have all seen when we have bought something in a shop, from books to groceries.

The passive RFID tags do not need a battery. When an RFID reader emits a radio-frequency wave to read the tag, the energy from the wave itself is enough to feed the tag chip. This makes the passive tags very cheap although it limits their cover to a maximum radius of approximately 2 or three metres.

One step further, the active and semi-passive RFID

The passive RFID has many advantages, mainly its cost and the fact that the tags do not need a battery, but it also has some very important limitations.

The semi-passive RFID tags do include a battery although for radio-frequency communication they still recur to the wave energy of the reader, the same as with the passive RFID.

In the case of the active RFID, the tags are completely autonomous as regards their supply since their battery also sees to feeding the communication by radio-frequency.

The active RFID is the most versatile. Thanks to the autonomous supply of the tags, their range can reach up to 100 metres. An active RFID tag can also start up communication itself and even communicate with other tags directly without needing a reader. If to all this we add the fact that temperature and humidity sensors can be integrated, the active RFID becomes a system which not only identifies products but can also monitor their condition constantly and communicate this information without having to unpack them.

In the case of perishable articles, the active RFID can check whether there have been any changes in temperature or humidity which could be damaging, both during their time on the metal racking and during transport. This is especially important for cold logistics and particularly for the food, health and pharmaceutical sectors.

FIFO and FEFO

By means of active RFID tags, a warehouse can easily get to know both the sell-by date of each product and the conditions it has undergone during its handling. In this way, besides using FIFO (First In, First Out) metal racking, in which the first product stored will be the first to be dispatched, the stockage can be optimised by taking into account which product will be the first to reach its sell-by date, even though it may not have reached the warehouse. This is known as FEFO (First Expire, First Out).

ATOX Storage Systems, a leader in the manufacture of metal racking, designs and adapts industrial racks to the specific needs of each warehouse.