WSSFC-AC is a Sigfox-Ready sensor with an integrated AC current measuring transducer that can measure the AC
current from a current transformer with max 5A AC current. It is compatible with any brand of current transformer (CT)
on the market which gives an output max of 5A AC. The CT ratio will be selected based on the load current.
It is battery-operated and able to connect to any Sigfox network in the World. It supports all frequency zones such as
RC1, RC2, RC3c, RC4, RC5, RC6, and RC7.
For the principle operation of the AC current sensor, please refer to
for typical applications.
The device will send uplink messages in the following cases:
Case 1: After power-up in the 60s, the device will send the first message called START_UP. The payload will tell
the user the HW version, FW version, and current configuration of the device;
Case 2: Then, in every interval time (pre-configured), for example, 10 minutes, it will send the message called
CYCLIC_DATA. The payload will tell the user the following data like measured value (AC current value), battery
level, alarm status...
Case 3: In case the Alarm function was enabled (in the configuration of the sensor), if the measured value
passed the threshold, it will send the uplink message immediately. This message is called ALARM. The payload
also tells the user the data like measured value (AC current value), battery level, alarm status...
Case 4: The HEART_BEAT uplink message will be sent once a day (the default setting, can be changed in
configuration) to allow the Sigfox back-end system can send the downlink message for changing the
configuration of the sensor. Please refer to the downlink section for more details. The uplink payload will tell the
user the HW version, FW version, and current configuration of the device;
Case 5: During commissioning, testing, or calibration sensor, the user can force the device to send the uplink
message so that they can get the data immediately. This message is called FORCE_DATA. The payload will
provide data like raw measured value, scaled measured value, battery level, alarm status... It can be forced by
applying the magnet key on the reed switch in 1s;
Case 6: In case users want to change the configuration immediately, they don't need to wait up to 1 day for the
HEART_BEAT message, instead they can force the device to send a special uplink message so that the device can
get the new downlink message. This uplink message is named PARAMETERS_UPDATE. It can be forced by
applying the magnet key in more than 5s.
The sensor was pre-configured at the factory with default values for configuration parameters that meet the most use
cases. However, depending on the specific use case, the customer can adjust those parameters. Please refer to
for more details.
The sensor is powered by 2 x AA 1.5V batteries for many years of operation. We do recommend using Energizer L91
battery which is very popular and high performance. This battery has a capacity of up to 3500mAh with a working
temperature range from -40 to +60 oC. The instruction for installing the batteries is in
.
For Battery life estimation, please refer to this link.
1.1.1 What are the typical applications of this sensor?
1.1.2 When does the device send uplink messages?
To change the cycle of data sending, you can change the value of the parameter: CYCLIC_DATA_PERIOD (default
is 600 seconds).
The alarm thresholds can be changed via downlink or offline tools.
1.1.3 The important configuration parameters
1.1.4 What kind of battery is used for this sensor?
