5
unique address and in order for the "2W RTU interface" to be able to differentiate
between the various RTUs, each RTU must have it's own address. So each output and
input in the 2 wired system will have it's location defined by 3 numbers: II;RR;L
–
"II" is the
address of the interface, "RR" is the address of the RTU and "L" is the location of the
specific output or input in the terminal block of the actual RTU. The addressing is done
by dipswitches onboard the interface and onboard each RTU. The range of the RTU
addresses is 1-60. The following drawing demonstrates the dipswitches block used for
addressing the RTUs:
The micro switches are numbered 1 to 6. Each micro switch according to it's ordinal number
represents a value between 1 and 32 as shown above. The values are used in the binary
coding system. The address is calculated by summing up the values of the micro switches
that are in the ON position. Appendix "A" supplies a conversion table from binary to decimal
and shows the setting of the switches required for each address.
2.4
DEFINITIONS TO BE MADE INSIDE THE DREAM
2.4.1
DECLARING THE 2W RTU INTERFACE
During system configuration the DREAM has to be told about the 2W RTU interface that is
connected to its "Remote I/O" line. This is done during the HARDWARE DEFINITION as
shown below:
2.4.2
DEFINING THE CONNECTIONS
During the definition of the physical connection point of each output and each input device,
the DREAM is told which of them reside on the 2W RTUs and where exactly each of them is
connected. An example can be seen below:
All outputs that have the interface
address "3" reside on the 2W RTUs.
Taking for example the Main valve No.
4, it has to be connected to RTU 7
position 1. A more detailed explanation
of this step can be found in the
"INSTALLATION MANUAL" of the
DREAM.
It is strongly recommended not to include in the connections definition
references to nonexistent RTUs. Otherwise each second the DREAM will try
to communicate the nonexistent units and when not receiving answer, it
will try again, causing all other units to wake up unnecessarily, this is a
significant waste of energy.
1
2
3
4
5
6
ON
1
2
4
8
16
32
The value represented
by each micro switch
Declaring
the 2W
interface
The
address of
the 2W
interface
Address of
Interface (II)
Number of
RTU (RR)
Location on
the board (L)
