BLUEBOX Gen.2 HFM
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1
Introduction
The
B
LUEBOX GEN2 INDUSTRIAL HF
hereinafter named
BLUEBOX
is a
read/write RFID device for industrial application (item 5233HM) that
communicates with a ‘host’ system (typically a PLC) through a PROFIBUS DP
serial line. The
BLUEBOX
acts as a joint through a set of commands between
the host system and the rfid tag/s (or transponder/s) present near the
antenna/s.
PROFIBUS DP (Dezentrale Pheripherie) was developed for high-speed
communication between central controllers (typically PLC)
and remote devices
(I/O, drives, actuators, sensors, ...).
More devices can be connected on the bus, each one has a different address
(the address is a configurable parameter). Once configured, the
communication with devices is cyclic.
Therefore the
BLUEBOX
is a remote device (‘slave’) with an input buffer and
an output buffer (the length of the buffers is a configurable parameter).
Similarly, in order to talk to the
BLUEBOX
, the PLC (‘master’) has an output
buffer (same size of the corresponding input buffer of the
BLUEBOX
) and an
input buffer (same size of the corresponding output buffer of the
BLUEBOX
).
The input buffer of the
BLUEBOX
can only be modified by the ‘master’ (PLC)
while the output buffer of the
BLUEBOX
can only be modified by the ‘slave’
that is the
BLUEBOX
. The aim of the cyclic communication is to keep up to
date the corresponding buffers at the ‘master’ side and at the ‘slave’ side.
At the application level, a specific protocol has been defined for enabling the
delivery of control messages from the PLC to the
BLUEBOX
and reply
messages from the
BLUEBOX
to the PLC.
For the developers: a .GSD (Generic Station Description) is provided that
defines the characteristics of the device and is necessary for the configuration
of the profibus network.
