What Is Proximity Tag Technology - Centsys Lattice Installation Manual

What is Proximity Tag technology?

What is Proximity Tag technology?
The word "proximity" means "close to" or "near". Thus a tag has only to be brought "near" or within a
certain range of the reader before it is read. There is no physical contact between tag and reader. The read
distance is typically in the range 60 to 100 mm.
The system uses RFID (Radio Frequency IDentification) technology. The reader has an antenna which
sends out a weak radio signal. The tag also has an antenna (a small coil) that receives the reader signal
as soon as it is in range. The tag absorbs some of the energy from the reader signal and powers up the
electronic circuit on the tag. There is no battery in the tag and it is thus known as a "passive" tag. An
"active" tag has a battery and is used in applications requiring greater "read" ranges.
The electronics of the tag reads the unique serial number of the tag and transmits this serial number, back
to the reader.
The reader receives the signal and checks to see if the tag serial number is one that is stored within its
memory as a "valid" tag. If the tag is valid the reader operates a relay to unlock a door, open an automatic
gate, or switch on some device. Instead of tags one can also have credit card sized cards. The principle
of operation is identical. Centurion Systems (Pty) Ltd has concentrated on the passive plastic tag instead
of the card which is bigger and bulkier.
Basic concepts
Before describing the L1000 system in detail some basic terms and concepts are explained.
L1000 Controller: The "Master" controller in the system which can be used as a standalone reader head,
or can be interfaced with remote slave heads.
Lattice slave head (LSH): A Lattice slave head is an auxiliary head that must be networked to a L1000
Controller head using a RS 485 network. Up to 31 LSH's can be linked to a single L1000. A remote slave
head cannot operate as a stand alone head although it has the capability to respond to a maximum of 40
"supervisor" tags in an off-line situation.
Take up head: A tag reader which also creates the interface between the L1000 and a computer running
Lattice Ware software.
Site: A site is defined as the geographical area where the L1000 access control system is located. E.g.
Bryanston School, Durban Branch office, etc.
Network: A network is defined as a single L1000 and its TUH and LSH's.
Area: An area is a physical area in which personnel work, or into which, or through which, they move.
E.g. Sales area, passage, classroom, etc. It is possible to have infinite areas at a site, but access to only
16 can be effectively controlled with the L1000 system. (The L1000 has a maximum of 32 readers split
between 16 entrance, and 16 exit, readers)
Zone: A zone is defined as an area, (or areas), which form a security level (or hierarchy). Thus, it is
possible to move through several areas, but remain in the same zone. Only 7 different zones are allowed,
but each tag (or user) can have its own series of zones associated with it. Thus an entrance lobby,
passage and office 1 could be defined as zone 1 for user 1, whereas the entrance lobby and passage
could be zone 1 for user 2, and office 2 might be defined as zone 2. Anti-pass back levels (defined below)
operate between zones.
Page 5