Develco SMSZB-120

Get started, scan, configure, mount and reset

Areas of use

Be sure to be notified on time with smart smoke detectors. Wattle smoke detector sends you alerts on your smartphone (Push alert, sms and email) when it detects smoke in addition to activating the audio signal from the siren. All sirens connected to Wattle are serial-connected. Enables one, activates all.


Get started

Step 1. Remove the battery cover as shown.

Step 2. The smoke detector will now start looking for a gateway (a ZigBee network).

Step 3. The LED will flash red while the smoke detector is looking for a gateway. (The smoke detector is in search mode 15min)

Scan for Smoke alarm

Step 1. Scan for new device in Wattle to connect it to your gateway. (Settings–>Manage devices)

Step 2. When the LED light stops blinking, the smoke detector is connected to a gateway and you will see it in the app.


Configure Smoke alarm

Step 1. Set a device name

Step 2. Add the device to a room.

Select the room you want from the list or add a new room.

Settings for: Fire Detector

Usage defaults to Security

Settings for: Temperature Sensor

Usage defaults to Generic

Step 3. Choose Apply

Placement of Smoke alarm

The smoke detector should be placed indoors at a temperature between 0 and 50 celsius.

It is important to install the smoke detector in bedrooms and at exits.

The distance between smoke detector and walls, ventilation openings or other obstacles should be at least 50 cm.

The smoke detector should be installed at least 4 meters from the fireplaces and stoves.

In rooms larger than 80 m2, one should install more smoke detectors to ensure the best possible fire protection.

The smoke detector should be positioned so that it is easily accessible to test the battery and for maintenance.

The smoke detector should not be mounted high in pointed roofs or roof corners. It should be placed at least 50 cm from walls.

Placement examples

Mounting Smoke alarm

Step 1. Take the smoke detector out of the socket by turning it counterclockwise.

Step 2. Use the pedestal to mark the shed holes in the ceiling or on the wall.

Step 3. Use the enclosed screws and plugs to install the mounting base.

Step 4. If the battery is not mounted or incorrect, it is not possible to attach the smoke detector to the base.

Step 5. Attach the smoke detector by turning it clockwise until you hear a click.

Testing Smoke alarm

Always test that the smoke detector works after installing and replacing the battery.

The smoke detector must emit a beep when a button is pressed on the smoke detector.

Test all smoke detectors once a week to ensure that they work properly.


Searching gateway mode

Red LED light in the back of the device is
flashing every second (up to 15 minutes)

Normal mode

Front LED is flashing every 45 seconds.

Low battery mode

Simultaneous audible signals and front LED
flashes every 45 seconds means that the
battery should be replaced.

Replace device mode

When audible signals and front LED flashes
are not simultaneous, the device should be
replaced. The life expectancy of smoke alarms
is generally 10 years, after which their sensors
begin to lose sensitivity.

Fault finding & cleaning

Dust particles in the smoke chamber can
be removed by vacuuming the mesh.

High humidity condensing can be resolved
by drying the smoke alarm.

If the smoke alarm does not work when the
test button is pushed, the probable cause
is a faulty battery. Replace the battery if it
is worn out.

In case of a bad or weak signal, change the
location of the smoke alarm. Otherwise you
can relocate your gateway or strengthen
the signal with equipment building mesh.

If the search for a gateway has timed out, a
short press on the LED button will restart it.


Resetting is needed it you want to connect
your smoke alarm to another gateway or if you
need to perform a factory reset to eliminate
abnormal behavior.

Step 1. Detach the alarm from the mounting base
by twisting it counterclockwise.

Step 2. Press and hold the LED button.

Step 3. While you are holding the button down, the
LED first flashes once, then two times in a
row, and finally numerous times in a row.

Step 4. Release the button while the LED is flashing
numerous times in a row.

Step 5. After you release the button, the LED shows
one long flash, and the reset is completed.

Technical specifications


  • Dimensions: Ø 65 x 40 mm
  • Color: White

Power supply

  • Battery: 1 x CR123, exchangeable
  • Battery life: 3 years, reporting every 5 minutes


  • IP class: IP20
  • Operation temperature: 0 to +50°C
  • Relative humidity 10-95% non-condensing

Radio features

  • Sensitivity: -98 dBm
  • Output power: +8 dBm

Specifications smoke sensor

  • Optical
  • Siren output 85 dB/3m

Specifications temperature sensor

  • Range: 0 to +50°C
  • Resolution: 0.1°C (accuracy ± 0.5°C)


  • RoHS compliant according to the EU Directive 2002/95/EC
  • DIN EN 14604 and 14676 certified
  • ZigBee Home Automation certification
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