Cws button and led behavior, 1 sensor link to base station, 2 sensor battery voltage – Campbell Scientific Wireless Sensor Network (CWB100, CWS220, and CWS900) User Manual

Page 45: 3 cws sensor search for base station

Wireless Sensor Network

5. CWS Button and LED Behavior

The Setup button on the back of a CWS sensor and the RED and BLUE LED
lights provide diagnostic information regarding the sensor and its
communication with the CWB100 base station radio.

5.1 Sensor Link to Base Station

Press the Setup button momentarily to see how the CWS sensor is linked to the
CWB100 base station. The RED LED flashes to indicate the number of hops
to the base radio as follows:

No RED LED flashes:

no link to base

1 RED LED flash:

direct (1 hop) link to base

2 RED LED flashes:

link through 1 repeater to base (2 hops)

3 RED LED flashes:

link through 2 repeaters to base (3 hops)

4 RED LED flashes:

link through 3 repeaters to base (4 hops)

These flashes do not provide any information regarding the strength of the
radio communication. They simply tell how many hops are required for the
sensor to reach the CWB100 base station. Signal strength is measured when
the datalogger executes a CWB100RSSI( ) instruction (See Section 4.4).

5.2 Sensor Battery Voltage

After pressing the Setup button momentarily the RED LED flashes if
connected to the base as described above, while the BLUE LED flashes
simultaneously to indicate battery voltage as follows:

1 flash:

Battery voltage < 2.25V; batteries should be replaced or recharged

2 flashes: 2.25V < Battery voltage < 2.50V

3 flashes: 2.50V < Battery voltage < 2.75V

4 flashes: Battery voltage > 2.75V

5.3 CWS Sensor Search for Base Station

If the Setup button is held for about four more seconds after the link/battery
status flashes have stopped, the BLUE LED will begin flashing about once per
second, and the radio will attempt to find a link to the base station. This
process is called auto-discovery. It will do this even if it already has a link to
the base.

The sequence for the search is:

1. Attempt to link to base. The search attempt takes from 30 seconds to 5

minutes. During this time the BLUE LED blinks about once per second.