CHAPTER 4
Understanding connectors
23
The RTU connectors
The addIT RTU uses standard 7-pin sensor I/O A and I/O B con-
nectors (model Binder 702 and 712 series or equivalent) that are
identical. Each connector contains three analog inputs (0 to 2.5
volt) and two digital input/outputs, one of which you can use as a
pulse counter (for example, a rain gauge). Figure 7 illustrates the
individual pins of an I/O connector.
Figure 7. Pins on an I/O Connector (Top View)
If you have a special passive extender cable, you can use it to plug
more than one sensor to one connector.
CAUTION To avoid cabling conflicts, first verify in the
addVANTAGE software that the sensor combination in the
configuration you want is allowed. If there are no conflicts, you can
physically attach the sensors to the addIT RTU.
addIT RTUs can also be used to control actuators and to switch on
or off pumps, valves, or other similar devices (for example, using
the Macro extension). The same principles for macro commands
using an A730MD remote measuring devices apply to addIT RTUs,
with the sole difference that instead of three, only the first two out-
puts are available.
Table 2. addIT Receiver Pin Functions
1 Bus Power (V+)
2 Bus Power (GND)
3 Bus Communications (B)
4 Bus Communications (A)
Cabling 1
Cabling 2
Cabling 3
Ground
Switched Battery
Digital I/O
Pulse Counter
1
2
3
4
5
67
(Analog In)
(Analog In)
(Analog In)