When mulling over a data center asset management system that uses RFID technology, one of the first things to consider is what flavor of tag to use. The technology underpinning both active and passive tags has advanced significantly in recent times and sussing out the capabilities of each tag type will help you pick the one that's right for you.
Active tags have a power supply so their signals are stronger than their passive cousin's. It also means they're constantly emitting a signal. That makes them easier to find than passive tags which must be in close proximity to an RFID reader before revealing their presence.
Moreover, because an active tag's signal is stronger, it can often surmount any local electromagnetic interference that would mask the signal from a passive tag. Because of that, any tagging projects that involved metal required the use of active tags. That advantage, though, has been offset in recent times by the introduction of passive tags designed to be attached to metal.
Another benefit of having a battery is that live information is easier to capture because the tag is "on" all the time. So active tags, in addition to broadcasting identification information, can capture and broadcast info that data center operators will find very useful; data such as time, temperature, and GPS coordinates.
As attractive as active tags are, they can't match their passive counterparts in several areas. Passive tags, being less complex than active ones, cost less—no insignificant consideration when thousands of assets may need to be tagged. This is one of the reasons passive RFID tags are used with our Vertices and VaultLedger products.
In addition, passive units are smaller so they take up less surface area on an object. What's more, since they don't have any batteries to replace—an expensive and labor intensive downside for active tags—they can be used indefinitely with minimum or no maintenance.