A label, a reader, and a record of the moment they met.
RFID is simpler than it sounds. Three things are involved, and what they produce between them is not a position on a map but a list of sightings.
- A label on each item
- Readers where items pass
- A record of each read
- No battery in the label
What happens at a read.
- Step 1
The label waits
An RFID label is a small aerial and a chip that holds a number. It has no power of its own and does nothing until a reader is near.
- Step 2
The reader asks
A reader sends out a radio signal. That signal is what powers the label, for the instant it takes to answer with its number.
- Step 3
The read is recorded
The platform notes which label answered, which reader heard it and when. That record is the whole of what RFID produces.
- Step 4
The record is put to use
One read says an item was seen. Many reads, set against what a document said should pass that door, say whether the day went to plan.
Why the label needs no battery.
A GPS tracker and a Bluetooth beacon both carry a battery, because both transmit by themselves. An RFID label borrows its power from the reader that is asking, so there is nothing inside it to charge or to replace.
That is why a label can be thin enough to stick on a carton, and why it suits items that exist in their thousands. It is also why a label is silent everywhere else. With no reader in range there is no power, and so no signal.
What a read tells you, and what it does not.
| A read tells you | A read does not tell you |
|---|---|
| Which label was read | Where the item went afterwards |
| Which reader read it: a door, a dock, a handheld or a vehicle | Where the item is at this moment |
| When it was read | Anything about an item that was not read |
That last line is why, in InSight RFID, a missed read never changes stock on its own. It is put to a person.
Closer to a barcode than to a tracker.
It is tempting to measure RFID against a GPS tracker and find it wanting. The fairer comparison is with a barcode, because both identify an item at a point. The difference is in the reading: a barcode has to be found and scanned, one at a time, while RFID labels are read by radio.
- Read by radio, with no need to see the label
- Many labels read together
- Nobody stops to scan each item at a fixed reader
Next
Ask about RFID for your clients.
Tell us what your client wants recorded item by item, and where those items pass. We answer with where InSight RFID stands, whether early access suits the job, and what the rest of the platform would add.