EDL21 Electricity meter LoRaWAN Bridge

The EDL21 over LoRaWAN bridge is a device that can be used to readout modern utility meters with standardized infrared "INFO" interface.

These type of meters are called in Germany to be "EDL21"-compatible - hence the name. The meter outputs over its infrared "INFO" interface a serial protocol conforming to the Smart Meter Language Protocol 1.04 (SML). This interface is intended to be used by end-users and not for billing purposes of the electricity supplier. The read information normally contains the current consumption values of the meter and gets interpreted and forwarded by the EDL21 bridge via a LoRaWAN network to web based applications interested in further processing this data.

Top Features

 LoRaWAN 1.0.x and 1.1 network servers supported

 LoRaWAN time synchronisation

 Configuration via USB or remotely via LoRaWAN downlink

 Compatible with many electrical utility meters

Configure up to 25 Obis Codes to be read

 RGB Status LED

 Variant with external power-supply available on request

 Separation of infrared readout head and LoRaWAN antenna possible

Compatible utility meters

On request we offer also the integration of electricity meters using the D0 interface conforming to IEC 62056-21. This interface is not compatible to the SML protocol. Please contact us if you need an offer for a custom firmware supporting your meter of interest.

Product variants

EDL21-LoRaWAN Bridge (universal head, XH battery connector, int. Ant.), Order number: 8000091
 

Quickstart

1. Connect to the device with the Lobaro Tool using the Lobaro Config Adapter
2. Under Configuration click "Reload Config" and change the fields ReadCron and ObisCode as you need followed by clicking on "Write to Device", here you can see a configuration example.
   
3. Register the device in your LoRaWAN network
4. Connect ER34614 3.6V D-cell Battery via XH connector / Connect external powersupply
5. If not connected to anything the red LED will start blinking as long as no data is received, after 1 minute it will sleep for 15 seconds after every 5 retries
6. Tighten the screws and install the bridge beside your electric meter
7. Place the EDL21 opto head on the "Info" interface
8. As soon as the EDL21 receives data its green LED will light up for 5 seconds, when connected to a LoRa Network its blue LED will light up for 5 seconds
9. Check the sent data (port 3), if payload is zero the EDL21 was not able to read data, recheck proper alignment

Configuration

The configuration is done using Lobaro Maintenance Tool and the Lobaro USB PC adapter.

LoRaWAN

The connection to the LoRaWAN network is defined by multiple configuration parameters. This need to be set according to your LoRaWAN network and the way your device is supposed to be attached to it, or the device will not be able to send any data.

For a detailed introduction into how this values need to be configured, please refer to the chapter LoRaWAN configuration in our LoRaWAN background article.

Operation

Configuration values defining the behaviour of the device.

See also our Introduction to Cron expressions and our Introduction to Obis Codes.

LED blinking patterns

The following pattery are explained in the order in which they appear after initial power on / reset of the device.

As you can see by this the device will start the LoRaWAN join only after receiving optical data at least once.

Appendices

Technical characteristics

Disposal / WEEE / Entsorgung

Information about the disposal of the Device.

Payload Format Status Packet (Port 1)

Once per day a status packet will be sent. It contains basic information about the device. The Battery Voltage is transmitted in 1/1000 V and the temperature in 1/10 °C. Both are in Big Endian byte order.

Payload Format 0 (old, Port 2, without exponent)

This payload was used by previous versions of the firmware and is not supported in the current version.

The payload consists of multiple entries, one entry per OBIS code given in the configuration. Each entry follows the following structure:

Example packet: 01 00 01 08 00 FE 08 FF 01 00 00 00 00 00 00 01 00 01 08 00 FE 08 FF 02 00 00 00 00 00 00

Entry 1:

Entry 2:

Payload Format 1 (new, Port 3, with exponent)

This Format is used, when the configuration parameter PayloadFormat is set to 1 (which is the default value).

The payload consists of multiple entries, one entry per OBIS code given in the configuration. Each entry follows the following structure:

Example packet: 01 00 01 08 00 FE 08 FF 01 00 00 00 00 00 00 ff 01 00 01 08 00 FE 08 FF 02 00 00 00 00 00 00 02

Entry 1:

Entry 2:

Multiple messages

The Bridge puts as many values in a single data message as possible (respecting the current Spreading Factor). When it cannot fit all values in a single message, it will send multiple data messages until all values are uploaded. It will never split a single value. Since every value is prefixed with the Obis code, the parser can easily assign values to Obis codes.

Reference decoder

This is a decoder written in JavaScript that can be used to parse the device's LoRaWAN messages. It can be used as is in The Things Network.

function readName(bytes, i) {
    return bytes.slice(i, i + 6);
}

function readValue(len, bytes, i) {
    if (len <= 0) {
        return [];
    }
    return bytes.slice(i, i + len);
}

function toHexString(byteArray) {
    var s = '';
    byteArray.forEach(function (byte) {
        s += ('0' + (byte & 0xFF).toString(16)).slice(-2);
    });
    return s;
}

function parse_int8(bytes, idx) {
    bytes = bytes.slice(idx || 0);
    var t = bytes[0];
    if ((t & 1 << 7) > 0) { // temp is negative (16bit 2's complement)
        t = ((~t) & 0xff) + 1; // invert 16bits & add 1 => now positive value
        t = t * -1;
    }
    return t;
}

function parse_int16(bytes, idx) {
    bytes = bytes.slice(idx || 0);
    var t = bytes[0] << 8 | bytes[1] << 0;
    if ((t & 1 << 15) > 0) { // temp is negative (16bit 2's complement)
        t = ((~t) & 0xffff) + 1; // invert 16bits & add 1 => now positive value
        t = t * -1;
    }
    return t;
}

function parse_uint16(bytes, idx) {
    bytes = bytes.slice(idx || 0);
    var t = bytes[0] << 8 | bytes[1] << 0;
    return t;
}

function toNumber(bytes) {
    var res = 0;
    for (var i = 0, s = 0; i < bytes.length; i++) {
        res |= bytes[i] << s;
        s += 8;
    }
    return res;
}

function readVersion(bytes) {
    if (bytes.length < 3) {
        return null;
    }
    return "v" + bytes[0] + "." + bytes[1] + "." + bytes[2];
}

function decodeStatus(bytes) {
    var decoded = {
        "version": readVersion(bytes),
        "flags": bytes[3],
        "vBat": parse_uint16(bytes, 4) / 1000,
        "temp": parse_int16(bytes, 6) / 10,
    };


    return decoded;
}

function decodeSmlValuesV1(bytes) {
    var decoded = {
        values: [],
    };

    if (bytes.length === 1) {
        // No Data! Read error?
        return decoded;
    }

    var pos = 0;
    while (pos < bytes.length) {
        var name = readName(bytes, pos);
        pos += 6;
        var len = bytes[pos];
        pos += 1;
        var value = readValue(len, bytes, pos);
        pos += len;

        var val = {
            nameHex: toHexString(name),
            len: len,
            value: toNumber(value),
            valueHex: toHexString(value)
        };

        decoded.values.push(val);
    }

    return decoded;
}

function decodeSmlValuesV2(bytes) {
    var decoded = {
        values: [],
    };

    if (bytes.length === 1) {
        // No Data! Read error?
        return decoded;
    }

    var pos = 0;
    while (pos < bytes.length) {
        var name = readName(bytes, pos);
        pos += 6;
        var len = bytes[pos];
        pos += 1;
        var value = readValue(len, bytes, pos);
        pos += len;
        var exponent = 1;
        var val = {};
        if (len > 0) {
            exponent = parse_int8(bytes, pos);
            pos += 1;
            val = {
                nameHex: toHexString(name),
                len: len,
                value: toNumber(value) * Math.pow(10, exponent),
                valueHex: toHexString(value),
            };
        } else {
            val = {
                nameHex: toHexString(name),
                len: len,
                value: toNumber(value),
                valueHex: toHexString(value),
            };
        }

        decoded.values.push(val);
    }

    return decoded;
}

// Test input (Port 3): 01 00 01 08 00 FE 08 FF 01 00 00 00 00 00 00 FF
function Decoder(bytes, port) {
    // Decode an uplink message from a buffer
    // (array) of bytes to an object of fields.
    switch (port) {
        case 1:
            return decodeStatus(bytes);
        case 2:
            return decodeSmlValuesV1(bytes);
        case 3:
            return decodeSmlValuesV2(bytes);
    }
}

// Wrapper for niota.io
/*
module.exports = function (payload, meta) {
    const port = meta.lora.fport;
    const buf = Buffer.from(payload, 'hex');

    return Decoder(buf, port);
}
*/

Example parser result

Test input (Port 3): 01 00 01 08 00 FE 08 FF 01 00 00 00 00 00 00 FF

{
  "values": [
    {
      "len": 8,
      "nameHex": "0100010800fe",
      "value": 51.1,
      "valueHex": "ff01000000000000"
    }
  ]
}

CE Declaration of Conformity

CE Declaration of Conformity (pdf).