C
HAPTER
2
R
EADER
F
UNDAMENTALS
R
EADER
I
NTERFACE
G
UIDE
D
OC
. C
ONTROL
# 8101938-000 R
EV
05
11
<Alien-RFID-Reader-Heartbeat>
<ReaderName>Alien RFID Reader</ReaderName>
<ReaderType>
Alien RFID Tag Reader, Model: ALR-9780
(Four Antenna / EPC Class 1 / 915 Mhz)
</ReaderType>
<IPAddress>10.1.60.5</IPAddress>
<CommandPort>23</CommandPort>
<HeartbeatTime>30</HeartbeatTime>
<MACAddress>01:02:03:04:05:06</MACAddress>
</Alien-RFID-Reader-Heartbeat>
H
EARTBEAT
XML T
AGS
ReaderName
is the user-defined name associated with the reader. This name
can be set by a user to help identify which reader is which.
For example, multiple readers in a warehouse may be named “loading bay 1”,
“loading bay 2” etc., thus providing a clear indication as to the physical location of
the reader.
ReaderType
details the specific type of reader sending out the heartbeat. This
information is hard-coded into the reader’s firmware and is not user-configurable.
IPAddress and CommandPort
elements detail the location of the reader on the
network. The IP address is simply the network address of the reader. The
command port is the port number on which the reader is listening for incoming
user commands. Typically, this is port 23, the standard telnet port, allowing a
user to communicate with the reader over the network by typing “telnet
[IPAddress]” into the command line of most computers.
HeartbeatTime
is the time until the next heartbeat. This time (in seconds)
enables any application software to detect when a reader is powered-down or the
network connection breaks; if a new heartbeat is not received after the expected
time elapses, then such an interruption to normal service can be detected.
MACAddress
gives the unique identifier assigned to the reader's network
interface hardware by the manufacturer. It is provided in the ALR-9800 and ALR-
9774 heartbeat messages only.
H
EARTBEATS AND
S
OFTWARE
The RFID Developer’s Kit CD that may accompany the reader provides source
code and software libraries to listen for these network heartbeats, in the Java,
.NET, and Visual Basic languages.
The
Alien RFID Gateway
application, bundled with all readers, uses the Java
version of these libraries to build its active reader list on the main screen. The
latest Gateway version at the time of this writing is v2.14.13. Alien recommends
users download the install the latest version of Gateway software.
TagList Concepts
During normal operation, the reader always has a concept of "what's out there"
by maintaining an internal list of the tags that are
active
. Active tags are those
read by the reader at least once within a predefined interval. Any new tags
presented to the reader are added to the list, and any tags that have not been
seen for a period of time (the PersistTime) are removed from the list.
Summary of Contents for ALR-8780
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