6
The picture above shows the inner part of a
DREAM 2
controller. It must be pointed out that
due to the flexible structure of the
DREAM 2
system, the construction of a controller may vary
from one case to another, depending on the specific needs.
In our example it can be seen that the controller is of the type powered from the mains through
the transformer. We can see the
Power supply board
that is in charge of generating the
various types of voltages used in the system. We can see the
Mother board
which combines
the various parts of the system together. Plugged into the bottom of the
Mother board,
there
are two interfaces, one is the
Local I/O Interface
and the other is the
RF Interface
. The
Local I/O Interface
is in charge of the
Local I/O boards
, in this example there is one
Local
I/O board
16/8
(16 outputs and 8 inputs). The
RF Interface
is coordinating between the
CPU
and the
Master
receiver transmitter which is in charge of the communication with the
radio
RTU
s in the field.
To demonstrate the flexibility of the
DREAM 2
system we shall bring another example of a
controller which is designed for powering by solar energy (it does not contain a transformer) its
power supply board is of the DC type and in this case the local I/O interface controls two
Local
I/O boards
16/8
that makes 32 local outputs and 16 local inputs.
When the system contains more interfaces than can be plugged into the mother board, they will
be installed externally and they will be connected by two wires to the
Remote I/O
plug
(RS485) on the mother board for communication and by another two wires to an energy source
of 12v DC.
DC power
supply board
Local I/O
interface
Local I/O
board 16/8
Local I/O
board 16/8
Remote I/O
plug
