1. Overview

Model catalog

Search for these models in ThinkLink by name or ID.

Model type	Name	id_name	Platform model ID
Template	ZENNER-BATTERY-21121		71880621491752965
Thing Model	[ZENNER] water	zenner_21121	71719731542888453
Thing Model	[ZENNER-21121-ZENNER资产] 区域聚合	zenner_asset_21121	119677189950959627
Parameter Thing Model	[ZENNER-PARA]	zenner_para_21121	111417969946292224

EdgeBus code

This is the original EdgeBus code used by the device.

import { Buffer } from "buffer";
import { buildOtaFile } from "@EBSDK/run";
import {
    ActionAfertExpr, CalcData,
    CrcMode,
    CvtRule,
    EBBuffer,
    EBModel,
    ExprCondition,
    LoraUpEvent,
    QueryEvent, SetUpCovDataType,
    UserConfUPItem,EventInfoItem
} from "@EBSDK/EBCompiler/all_variable";
import { CheckbitEnum, getOtaConfig, HwTypeEnum, UpgrdTypeEnum } from "@EBSDK/otaConfig";
////////////////////////////////////////////////////////////////////////////////////////
const eventInfo:UserConfUPItem[]=[
    {
        name:"water",port:22,version:"0x83",dataType:"0x32",upPeriod:"10y",
        quInfo:[
            {
                protocol:"modbus",addr:"0x02",code:"0x03", periodIndex:70,
                indexAPP:150, indexCMD:0, copySize:1,payIndex:3,ackAddrIndex:0,
                listVal:[
                    { start: "0x0007", end: "0x0007",  },// EDC 电压状态 2字节：0x0007（低字节含状态码：FF/01/02 等，按手册解释）type: "Uint16BE"
                ]
            },
            {
                protocol:"modbus",addr:"0x02",code:"0x03", periodIndex:70,
                indexAPP:150, indexCMD:0, copySize:1,payIndex:3,ackAddrIndex:0,
                listVal:[
                    { start: "0x0008", end: "0x0008",  },//EDC 报警信息 2字节：0x0008,type: "Uint16BE"
                ]
            },
            {
                protocol:"modbus",addr:"0x02",code:"0x03", periodIndex:70,
                indexAPP:150, indexCMD:0, copySize:1,payIndex:3,ackAddrIndex:0,isLast:true,
                listVal:[
                    { start: "0x0004", end: "0x0005"   }, // type: "FloatBE"
                ]
            }
        ]
    }
]
let otaConfig = getOtaConfig({
    BaudRate: 9600,
    StopBits: 1,
    DataBits: 8,
    Checkbit: CheckbitEnum.EVEN,
    Battery: true,
    ConfirmDuty: 60,
    BzType: 21121,
    BzVersion: 16
})
const MODBUS_TT = (ebModel: EBModel) => {
    for (let i=0; i<eventInfo.length; i++){
        let event=new EventInfoItem(eventInfo[i]);
        event.upEventSetup()
        event.eventInstall()
    }
    return JSON.stringify(ebModel, null, 2)
}
buildOtaFile(import.meta.url, otaConfig, MODBUS_TT)

This document describes the complete integration solution for ZENNER water meters (DN25 / DN40) connected via KC21 data collector, using Modbus-RTU protocol and EB framework, and integrated into the ThinkLink platform.

The document includes:

• Device wiring and communication parameters
• ThinkLink platform usage instructions
• Telemetry data format and third-party subscription
• Advanced EB integration details (EBHelper, Thing Model, RPC)

---

Part 1: User Guide

---

2. Meter Device Information

2.1 Water Meter Specifications

• Brand: ZENNER
• Device Type: Water Meter
• Models: DN25 / DN40
• Power Supply: External power required
• Input Voltage: DC 12–24V

---

2.2 Communication Parameters (RS485 / Modbus-RTU)

Parameter	Value
Protocol	Modbus-RTU
Baud Rate	9600 bps
Data Bits	8
Parity	Even
Stop Bits	1
Slave Address	Configurable

---

2.3 Water Meter Wiring

Wire Color	Description
Red	Power +
Black	Power −
Yellow	RS485 A
Green / Blue	RS485 B

---

2.4 Official Manuals

• https://active.clewm.net/E1Jg6l
• https://active.clewm.net/EeFfJo

---

3. Data Collector Information (KC21)

3.1 Basic Information

• Model: KC21
• Power Supply: Battery powered
• External Power Output: 15V (for meter power supply)

---

3.2 KC21 Wiring

Wire Color	Description
Red / Brown	Power +
Black	Power −
Blue	RS485 A
White	RS485 B

⚠️ Ensure RS485 A/B lines are connected correctly between the KC21 and the water meter.

---

4. ThinkLink Platform Usage

---

4.1 Add Device

1. Log in to the ThinkLink platform
2. Go to Device Management → Add Device
3. Search and add the following model:

ZENNER-BATTERY-21121

4. Complete device binding

---

4.2 Parameter Configuration

Navigation path:

Device Management → Select Device → Configuration → RPC

Select RPC:

[EB SET] easy para

Parameters

Parameter	Description
period	Meter reading interval (seconds)
addr	Modbus slave address of the water meter

---

4.3 Third-Party Data Subscription

MQTT Topic

/v32/{Organization Account}/tkl/up/telemetry/{eui}

Sample Telemetry Payload

{
    "eui": "6353012af10a9331",
    "active_time": "2026-02-05T08:35:48.000Z",
    "thingModelId": "71719731542888453",
    "thingModelIdName": "zenner_21121",
    "telemetry_data": {
        "snr": 13.5,
        "rssi": -51,
        "battery": 3.37,
        "total_flow": 1,
        "update_time": 1770280548000
    }
}

Protocol Reference

• http://think-link.net/tkl-docs/zh/Protocol/ThinkLinkProtocol.html

---

Part 2: Advanced Integration

---

5. Data Acquisition via EBHelper

5.1 Communication Protocol

• Protocol: Modbus-RTU
• Implementation: EBHelper
• Business Type (BzType): 21121

---

5.2 Modbus Register Mapping

Register Address	Description	Data Type
0x0007	EDC voltage status	Uint16BE
0x0008	EDC alarm status	Uint16BE
0x0004–0x0005	Total water consumption	FloatBE

---

5.3 OTA Configuration

let otaConfig = getOtaConfig({
    BaudRate: 9600,
    StopBits: 1,
    DataBits: 8,
    Checkbit: CheckbitEnum.EVEN,
    Battery: true,
    ConfirmDuty: 60,
    BzType: 21121,
    BzVersion: 16
})

---

5.4 EB Compilation Logic

• EBHelper is used to define Modbus polling logic
• Event configuration is defined in eventInfo
• OTA file is generated using buildOtaFile()
• Supports periodic Modbus polling and LoRa uplink

---

6. Thing Model Mapping

6.1 Uplink Frame Structure

Port: 22

Uses the EBHelper standard frame format:

Field Name	Offset	Length (Bytes)	Description
version	0	1	Protocol version, fixed at 0x83
dataType	1	1	Fixed at 0x32
covStatus	2	1	Reserved byte (for internal COV processing)
status	3	1	Query event status
battery	4	1	Battery level
addr	5	1	Sub-device address
EDC Voltage	6	2	Big-endian format, Uint16BE
EDC Alarm	8	2	Big-endian format, Uint16BE
Total Flow	10	4	FloatBE, unit: m³

6.2 Thing Model Information

Item	Value
Thing Model Name	ZENNER
Thing Model ID Name	zenner_21121
Event Name	water

---

6.2 Field Mapping

Field	Description
total_flow	Total water consumption
battery	Battery voltage
rssi	Signal strength
snr	Signal-to-noise ratio

---

7. Payload Parsing Logic

7.1 Telemetry Parsing

• LoRa Port: 22
• Data Type: FloatBE
• Precision: 3 decimal places

---

7.2 Parameter Parsing (RPC)

APP Address	Parameter
70	Polling interval (period)
150	Modbus slave address

---

8. RPC Parameter Configuration

• RPC Name: [EB SET] easy para
• RPC ID Name: eb_set_easy_para

APP Address	Description
app_70	Polling period
app_150	Water meter Modbus address

---

9. Summary

This solution provides a complete and reliable integration of ZENNER water meters into the ThinkLink platform using EB + KC21:

• Remote parameter configuration
• Periodic meter reading
• Standard MQTT telemetry for third-party systems
• Low power consumption and high stability

It is well suited for water management, irrigation automation, and smart utility projects.