Adcom A720, A723 , More about the LED tool

CHAPTER 3

Using the RTU

This completes the installation of your addIT RTU. If one of the

I/O

connectors is left unused, use the cap specially provided to protect

it against moisture and dust. Be sure to make a note of the follow-

ing information because you’ll need it when you conﬁgure the

device in the software:

• Serial number for each RTU

•Type of sensors connected to each RTU

More about the LED tool

The LED tool allows you to rapidly check the status of an addIT

RTU. After you insert the LED tool into the POWER connector, the

unit waits up to two seconds and then sends a broadcast frame. If a

nearby listening station or receiver decodes the frame, it will

answer back—this may take up to 10 seconds. When an answer is

received, the LED tool lights up for about 4 seconds. After another

few seconds, the LED lights up one or more times, depending on

the number of stations/receivers that answered to its broadcast

frame.

Note: addIT RTUs do not respond to a broadcast frame, only

remote stations (A730MD) and base stations (A730SD or

A720B).

In addition, the LED always blinks brieﬂy at 0.5 second intervals to

indicate that the unit is alive and the internal battery has enough

energy to operate. If the blinking interval lengthens to 2 seconds,

the battery has become undercharged (that is, under 5.6 volts but

over 5.2 volts)—this is called the

misery

state. In this state, an

addIT RTU reduces its activities to a minimum. The radio unit is

switched off, the sensor sampling ceases, and no data is stored in

the internal memory. Only the internal real-time clock is maintained

and the power management functions are performed.

If the battery level drops below 5.2 volts, the system switches com-

pletely off, effectively decoupling itself from the battery in order to

protect it. In this case the LED tool stays permanently off. An addIT

RTU in such a situation will restart only after connecting it to an

external power supply (even a solar panel under low light condi-

tions).

Note: New addIT RTUs are delivered with their internal batteries

unformatted, meaning they are completely discharged, and

you should install them only on sunny days. The battery will