Manual for Sigfox-Ready AC Current Sensor - WSSFC-AC | FW1.0

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Thank you very much for choosing Daviteq Wireless Sensors. We are the leading wireless sensor manufacturer in the World. We have a wide range of wireless sensors which support different connectivity like LoRaWAN, Sigfox, Sub-GHz, NB-IoT...Please find out more information at this link.

This manual is applied to the following products

Item code HW Version Firmware Version Remarks
WSSFC-AC-11 1.0 1.0  

Information Changes in this version v.s previous version

Item Changes Changed by Changed Date Approved by Approved Date
1 Initial version D.Q.Tuan 09-04-2022 N.V.Loc 28-06-2022

To use this product, please refer step by step to the below instructions.

1.  Quick Guide

Reading time: 10 minutes
Finish this part so you can understand and put the sensor in operation with the default configuration from the factory.

1.1 What is the Sigfox-Ready AC Current Sensor and its principle of operation?

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 this link.

1.1.1 What are the typical applications of this sensor?

Please refer to this link for typical applications.

1.1.2 When does the device send uplink messages?

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...

To change the cycle of data sending, you can change the value of the parameter: CYCLIC_DATA_PERIOD (default is 600 seconds).

  • 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...

The alarm thresholds can be changed via downlink or offline tools.

  • 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.
1.1.3 The important configuration parameters

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 section 3.2 for more details.

    1.1.4 What kind of battery is used for this sensor?

    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 this link.

    269032-aabatteries-energizer-ultimatelithiumaa.webp

    For Battery life estimation, please refer to this link.

    1.2 What's in the package?

    The package includes:
    01 x Main device
    01 x AC current measuring transducer M12 and cable
    01 x Magnet key
    01 x Wall mounting bracket and screws

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    1.3 Quick Test

    With the default configuration, the device can be connected quickly to the Sigfox Network by the following steps.

    Step 1: Prepare the values of communication settings:

    Device ID

    Get Devive ID on the device nameplate 

    Device PAC

    Get Devive PAC on the device nameplate 

    Note: All Sigfox sensors are pre-configured with the correct RC before delivery. The settings of Device ID, Device PAC, and RC could be also read from the device memory map. Please reference section 3.2 Sensor configuration for details.

    Step 2: Add the device to Sigfox Backend

    Please refer to this link for details

      Step 3: Install the batteries to the device

      Please refer to this link for instructions on battery installation.

      After installing the battery in 60 seconds, the first data packet will be sent to the Sigfox network. After receiving the first data packet, the time of another packet depends on the value of the parameter: CYCLIC_DATA_PERIOD. Additionally, you can use a Magnet Key to force the device to send data instantly.

      Step 4: Decode the payload of receiving package

      Please refer to section 1.4 Uplink Payload and Data Decoding for details of decoding the receiving packet to get the measured values.

      1.4 Uplink Payload and Data Decoding 

      Note: Please select the right Payload document to suit the FW version of the sensor

      1.5 Sensor Installation

      SAFETY ATTENTION:

      - TO REPLACE BATTERIES OR SERVICE THE MAIN DEVICE, PLEASE PAY ATTENTION TO THE ELECTRICAL SHOCK THAT MAY HAPPEN DUE TO THE PROBLEM OF THE AC CURRENT CABLE OR FAILURE OF THE CURRENT TRANSFORMER. FOR SAFETY REASONS, REMOVE THE AC CURRENT TRANSDUCER OUT OF THE MAIN DEVICE BY UN-SCREWING THE M12 CONNECTOR BEFORE OPENING THE PLASTIC HOUSING OF THE MAIN DEVICE;

      - ONLY QUALIFIED ELECTRICAL TECHNICIANS CAN HANDLE THIS DEVICE FOR INSTALLATION, MAINTENANCE, AND OPERATION;

      - USE THE HEAT-SHRINK PVC TUBE TO PROTECT THE CONNECTIONS ON THE CABLE OF THE AC CURRENT AND AVOID THE WATER CONTACT WITH THOSE ELECTRICAL CONNECTIONS.

      DIMENSIONS OF PRODUCT

      WSSFC-AC_en_4.jpg

      The Sigfox-Ready AC current sensor is a combination of a wireless transmitter and an AC current transducer. Therefore, the installation will be divided into 02 parts:

      • Installation for the wireless transmitter: these steps are to make sure the device sends data successfully;
      • Installation for AC current circuit: these steps are to make sure the device to measure correctly.

      Please follow the orders of steps strictly as below.

      1.5.1 Preparation of the locations
      • Locate the place to mount the CT, the place that is to measure the load current;
      • Locate the place to mount the Wireless transmitter to get the best RF signal. As the AC current transducer will be attached to the wireless transmitter, please make sure the cable length is enough for the distance from CT to the wireless transmitter;

        To get a strong RF signal please refer to this link.

      1.5.2 Wireless Transmitter Installation
      • Mount the wireless transmitter on the wall or outside the wall of the electrical panel. The antenna part must be higher than the highest point of the electrical panel. Then connect the grounding wire from the base of the wireless transmitter (if available) to the grounding system of the facility. Please check this link for the mounting guide;
      • Insert the batteries into the wireless transmitter and check the system to see whether the wireless transmitter already sent the first message to the system? Please follow this link to know how to install the batteries.

        ATTENTION:

        REVERSED POLARITY OF BATTERIES IN 10 SECONDS CAN DAMAGE THE SENSOR CIRCUIT!!!

      1.5.3 CT Installation
      • Shut down the main load before installing the CT
      • For closed-type CT, please shut down the main load before installing the CT.
      • For clamp-type CT, it is possible to install the CT onto the load wire, however, we highly recommend shutting down the main load for safety reasons.

      • Danger: be aware of electrical shock with AC voltage!
      1.5.4 Connect the CT with the AC current transducer

      Use the crimping tool to make the connection and protect the connection with a PVC heat shrink tube as this link.

      1.5.5 Connect the AC transducer to Wireless Transmitter

      Connect the AC transducer to the wireless transmitter via the M12 connector as this link.

      1.5.6 Device calibration

      The Sigfox-Ready AC current transducer is produced with accuracy as published in the specification of the product and is ready to use. However, the user can re-calibrate the sensor again when necessary, please follow the steps in this link.

      1.5.7 Turn on the Main load again

      After connecting, the sensor will send the data to the system with the value = zero (no AC current). Then you can turn ON the main load again to put the system into the operation.

      You can use a clamp-type ampere meter to validate the value reading from the system. Please make sure the two comparison values must be collected at the same time.

      2. Maintenance

      2.1 Troubleshooting

      • Problems with Sigfox communication like not receiving the packets...please refer to this link to troubleshoot the device.
      • Problems with the sensor functions like not measuring, or inaccurate measuring....please refer to this link to troubleshoot the sensor part.

      2.2 Sensor maintenance

      Maintenance works Yes/No

      Descriptions

      Consumable parts replacement No

      The Sigfox-Ready AC current sensor has no consumable part, so there is no need to replace any parts.

      Cleaning sensor or device No

       

      Re-calibration / Re-validation Yes The transducer may need to be re-calibrated when necessary. Please refer to this link for the procedure of calibration.

      3. Advanced Guide 

      3.1 Operating principle of the Sigfox-Ready AC current sensor

      3.1.1 Operating principle of the complete device

      The Daviteq Sigfox-Ready AC current sensor comprises 02 parts connected together as shown below picture.

      - The Daviteq Sigfox-Ready wireless transmitter;
      - The Daviteq AC 5A current Transducer; 

      WSSFC-AC-H1.jpg

      The AC current transducer is to measure the actual AC current of the secondary winding of the CT.

      The Sigfox-Ready is to read the AC current value from the transducer and perform the scaling (A and B values, during calibration). The scaled current will be multiplied by the CT ratio to deliver the final value which is the actual load current that the user wants to measure.

      Scaled_CT_Current = A x CT_Current + B

      Actual_Load_Current = Scaled_CT_Current x CT

      Where:

      A : Constant A

      B : Constant B

      CT_current: the measured current from the transducer (Secondary winding current of the CT)

      For example: the CT_current = 1.5A, the CT ratio = 20 (the CT is 100/5), A=1, B=0 ==> then the Actual_Load_Current = 1.5 x 20 = 30A

      Note: the Low cut value of Actual_Load_Current is 0.5A. That meant the device can not measure the current load less than 0.5A

      3.1.2 Operating principle of AC current transducer

      To understand how the AC current transducer can measure AC current, please refer to this link for a complete understanding of this measuring technique.

      3.1.3 Some important configuration parameters

      Below are some important configuration parameters which affect the operation of the device like battery life, measurement accuracy, and alert threshold.

      For Battery life estimation, please refer to this link.

      • measure_period | Default = 600s
        This is the time period for the wireless transmitter to wake up and take the measurement from the transducer. The default value is 600s. Users can reduce this value, but smaller value, shorter battery life!

      • cyclic_data_period | Default = 600s
        Interval time to send an uplink message regardless of any conditions

      • sensor_boot_time | Default = 1000mS
        This value will affect the measurement accuracy. DO NOT change this value!

      Those configuration parameters can be changed by downlink or offline tools. For more other configuration parameters, please refer to the next section.

      3.2 Sensor Configuration

      3.2.1 How to configure the Sigfox-Ready AC Current Sensor?

      Sensor configuration can be configured in 02 methods:

      • Method 1: Configuring via Downlink message. Please find the instructions in this link, but please take note of the FW version of the Document.
      • Method 2: Configuring via off-line cable.
      3.2.2 What parameters of the device are configured?
      • There are some parameters that are read-only, and some are read and writeable.
      • To read the parameters, use the off-line cable as above instruction.
      • Via uplink message, users can read only one parameter, which is the CURRENT_CONFIGURATION.

      Below tables are the lists of the parameters of the device.

      Read-only Parameter Table

      Modbus Register (Decimal)

      Modbus Register (Hex)

      Function Code (Read)

      No. of Registers

      Description

      Range

      Format

      Property

      Comment

      2

      2

      3

      4

      FW_VERSION

       

      string

      Read

       

      6

      6

      3

      2

      HW_VERSION

       

      string

      Read

       

      8

      8

      3

      2

      DEVICE_ID

       

      hex

      Read

      Product ID

      10

      A

      3

      4

      DEVICE_PAC

       

      hex

      Read

      Product PAC

      14

      E

      3

      1

      SENSOR_TYPE

      1-255

      uint16

      Read

      Sensor or Input Type

      Read/Write Parameter Table

      Modbus Register (Decimal)

      Modbus Register (Hex)

      Function Code (Read)

      Function Code (Write)

      No. of Registers

      Description

      Range

      Default

      Format

      Property

      Comment

      270

      10E

      3

      16

      4

      CURRENT_CONFIGURATION

       

       

      hex

      Read/Write

      Check the Payload Document section: 5.Payload for downlink message for more information

      274

      112

      3

      16

      1

      SERVER_CONFIG

       

       

      uint16

      Read/Write

      0: Send to Sigfox Network

      1: Send to Dongle

      276

      114

      3

      16

      1

      RADIO_CONFIG

      1-4

      4

      uint16

      Read/Write

      RC zones selection 1, 2 , 3, 4 is RC1, RC2, RC3s, RC4

      277

      115

      3

      16

      1

      TX_POWER

       

      20

      int16

      Read/Write

      RF Tx power

      278

      116

      3

      16

      2

      CONSTANT_A

       

      1

      float

      Read/Write

      Constant a for scaling measured value

      280

      118

      3

      16

      2

      CONSTANT_B

       

      0

      float

      Read/Write

      Constant b for scaling measured value

      282

      11A

      3

      16

      2

      HIGH_CUT

       

      1E+09

      float

      Read/Write

      High cut value for the calculated value

      284

      11C

      3

      16

      2

      LOW_CUT

       

      0,5

      float

      Read/Write

      Low cut value for the calculated value

      286

      11E

      3

      16

      2

      SENSOR_BOOT_TIME

       

      1000

      uint32

      Read/Write

      Boot time of sensor/input, in ms

      306

      132

      3

      16

      2

      CT

       

      40

      float

      Read/Write

      CT of current transformer

      3.3 Calibration for Sigfox-Ready AC current transducer

      Please refer to this link.

      4. Product specification 

      Please refer to the detailed specifications in this link.

      5. Warranty and Support 

      For warranty terms and support procedures, please refer to this link.

      6. References

      Use-cases:

      Case studies:

      White-papers:

      END.