ThinkLink

1. Sensor Overview

The AQ3485 is a dual-channel temperature sensor manufactured by AoQing (奥青). It uses a Modbus-RTU / RS-485 interface to simultaneously read refrigerator temperature and defrost temperature from a cold-storage unit. This integration connects the sensor to the ThinkLink platform via a KC21 (battery-powered) DTU, with optional COV (change-of-value) triggered uplinks.

Integration details: model AQ3485, business code 21306, template name AQ3485.

2. Product Features

Dual-channel temperature acquisition: refrigerator temperature + defrost temperature
RS-485 interface, Modbus-RTU protocol
Default slave address 0x01, baud rate 9600, 8N1
Independent COV thresholds for each temperature channel
Low power design — battery-powered KC21 DTU

3. Applications

The AQ3485 is suited for the following scenarios:

Cold cabinet monitoring in supermarkets and convenience stores
Refrigeration room and defrost temperature monitoring in cold-storage warehouses
Cold chain logistics temperature management
Cold storage equipment monitoring in food and pharmaceutical industries

4. Data Collector

4.1 Hardware Specifications

This solution uses the KC21 (battery version) DTU.

Model: KC21
Interface: RS-485
Power supply: Battery
LoRaWAN Class: A

4.2 Wiring

Power and Communication Interface

The KC21 battery version supplies power to the sensor over the RS-485 bus:

KC21 A terminal → RS-485A (sensor)
KC21 B terminal → RS-485B (sensor)

Sensor Interface

The AQ3485 uses a standard RS-485 interface with default settings: 9600 baud, 8N1, no parity. Connect directly to the KC21 RS-485 port.

5. Data Acquisition

This solution reads the following Modbus registers:

0x0000: Refrigerator temperature (Int16BE, × 0.1 °C)
0x0001: Defrost temperature (Int16BE, × 0.1 °C)

Platform parameter address conventions:

Upload interval: App address 70
Acquisition interval: App address 74
Power-on delay: App address 38

5.1 Register Map

Address (hex)	Description	Data Type	Notes
`0x0000`	Refrigerator temperature	Int16BE (signed, big-endian)	Raw value × 0.1 = actual temperature (°C)
`0x0001`	Defrost temperature	Int16BE (signed, big-endian)	Raw value × 0.1 = actual temperature (°C)

6. EdgeBus Model

6.1 EB Configuration

Parameter	Value
`name`	`"AQ3485"`
`port`	`21`
`version`	`"0x85"`
`dataType`	`"0x03"`
`upPeriodIndex`	`70`
`periodIndex` (acquisition)	`74`
`BaudRate`	`9600`
`StopBits`	`1`
`DataBits`	`8`
`Checkbit`	`NONE`
`Battery`	`true`
`BzType`	`21306`
`BzVersion`	`12`
`SwVersion`	`31`

6.2 EB Code

typescript

import {Buffer} from "buffer";
import {buildOtaFile} from "@EBSDK/run";
import {EBModel, EventInfoItem, LoraUpEvent, UserConfUPItem, CheckbitEnum, getOtaConfig, HwTypeEnum} from "@EBSDK/EBCompiler/all_variable";
////////////////////////////////////////////////////////////////////////////////////////
const eventInfo:UserConfUPItem[]=[
    {
        name:"AQ3485",port:21, version:"0x85",dataType:"0x03",upPeriodIndex:70,
        quInfo:[
            {
            protocol:"modbus",code:"0x03", periodIndex:74,//addr:"0x01",
            indexAPP:150, indexCMD:0, copySize:1,isLast:false,
            listVal:[
                { start: "1", end: "1" ,covType:"Int16BE",covAppIndex:110},  // refrigerator temp, coefficient=0.1
                { start: "2", end: "2" ,covType:"Int16BE",covAppIndex:112}   // defrost temp, coefficient=0.1
                ]
            }
        ]
    }
]
let otaConfig = getOtaConfig({
    SwVersion:31,
    BaudRate: 9600,
    StopBits: 1,
    DataBits: 8,
    Checkbit: CheckbitEnum.NONE,
    Battery: true,
    ConfirmDuty: 60,
    BzType: 21306,
    BzVersion: 12
})
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)

6.3 Notes

EB logic summary:

Uplinks are sent on port 21.
A single query event reads registers 0x0000 and 0x0001 in one Modbus FC03 request (2 contiguous registers, 4 bytes total).
Upload interval and acquisition interval are separated:
- App address 70 = upload interval
- App address 74 = acquisition interval
COV triggers: refrigerator temperature (App 110) and defrost temperature (App 112) each have independent COV thresholds. An uplink is triggered immediately when a temperature change exceeds its threshold.
The Modbus slave address is managed by App parameter 150 and can be changed at runtime.
Data format: Int16BE (signed, big-endian); divide by 10 to get temperature in °C.

7. Thing Model

7.1 Thing Model Information

Telemetry Thing Model

Name: [AQ3485]
id Name: aq3485_21306

7.2 Uplink Frame Structure

frameInfo: { port: 21, dataLen: -1, rssi: true, battery: 4 }
tagList:   [{ index: 0, tag: 0x85 }, { index: 1, tag: 0x03 }]

Uplink frame field layout (business data starts at byte 6):

Offset (index)	Field	Type	Unit	Description
0	version	uint8	—	Protocol version, fixed `0x85`
1	dataType	uint8	—	Business type, fixed `0x03`
2	covStatus	uint8	—	COV trigger status
3	status	uint8	—	Query event status
4	battery	uint8	—	Battery level (4-byte encoded)
5	addr	uint8	—	Modbus slave address
6–7	humidity	Int16BE	°C × 0.1	Refrigerator temperature (`field_name: humidity`)
8–9	temperature	Int16BE	°C × 0.1	Defrost temperature (`field_name: temperature`)

Field naming note: The humidity field contains refrigerator temperature, and temperature contains defrost temperature. These names reflect legacy platform registration and do not affect functionality.

7.3 Thing Model Script

7.3.1 Telemetry Thing Model Script

javascript

import {PayloadParser} from '#tklHelper';

function payload_parser({device, msg, thingModelId, noticeAttrs}) {
let    port=msg?.userdata?.port || null;
    let frameInfo={
        port:21, dataLen:-1,rssi:true,battery:4,
        tagList:[{   index:0, tag:0x85}, {   index:1, tag:0x03}]
    }
    let appInfo = [
        {   name: "humidity", field_name: "humidity", unit:"℃", index: 6, type: "int16BE",coefficient:0.1,decimal:1},
        {   name: "temperature", field_name: "temperature", unit:"℃", index: 8, type: "int16BE",coefficient:0.1,decimal:1},
    ]
    let paraInfo= {
        app_70: {name: "periodUP", field_name: "periodUP", unit: "s",  type: "uint32LE"},
        app_74: {name: "periodRead", field_name: "periodRead", unit: "s", type: "uint32LE"},
        app_110: {name: "cov_temperature", field_name: "cov_temperature", unit: "℃", type: "int16BE",coefficient:0.1,decimal:1},
        app_112: {name: "cov_humidity", field_name: "cov_humidity", unit: "℃", type: "int16BE",coefficient:0.1,decimal:1},
        app_150: {name: "addr", field_name: "addr", unit: "", type: "uint8"},
    }
    let pdata={}
    let tdata={}
    let payParser=new PayloadParser({
        device:device,
        msg:msg,
        frameInfo:frameInfo,
        appInfo:appInfo,
        paraInfo:paraInfo,
    })
    if (port===214) {
        pdata=payParser.paras()
        tdata=null
    }else  {
        tdata= payParser.telemetry()
        pdata=null
    }
    return {
        telemetry_data: tdata,
        server_attrs: null,
        shared_attrs: pdata
    }
}

8. Third-Party Platform Data Subscription

8.1 MQTT Topic

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

8.2 Example Payload

json

{
    "eui": "6353012af10a9331",
    "active_time": "2026-02-05T08:35:48.000Z",
    "thingModelId": "87554295540486149",
    "thingModelIdName": "aq3485_21306",
    "telemetry_data": {
        "snr": 10.5,
        "rssi": -65,
        "battery": 3.21,
        "humidity": -5.2,
        "temperature": 18.3
    }
}

Notes:

thingModelId uses the platform-assigned value (87554295540486149).
thingModelIdName maps to the telemetry thing model aq3485_21306.
humidity represents refrigerator temperature (°C); example value -5.2 °C is a typical cold-storage reading.
temperature represents defrost temperature (°C); example value 18.3 °C represents ambient temperature during a defrost cycle.

9. RPC

9.1 RPC Names

Set Parameters RPC

Name: [AQ3485 SET] para
id Name: AQ3485_21306_set

Get Parameters RPC

Name: [AQ3485 GET] para
id Name: aq3485_21306_get

9.2 Parameter Definition

App Address	Parameter Name	field_name	Unit	Type	Description
app_38	pwron_delay	pwron_delay	ms	uint16le	Power-on delay before querying the sensor
app_70	periodUP	periodUP	s	uint32LE	Upload interval
app_74	periodRead	periodRead	s	uint32LE	Acquisition interval
app_110	cov_temperature	cov_temperature	°C	int16BE	Defrost temp COV threshold (× 0.1 °C)
app_112	cov_humidity	cov_humidity	°C	int16BE	Refrigerator temp COV threshold (× 0.1 °C)
app_150	addr	addr	—	uint8	Modbus slave address (default: 1)

9.3 RPC Scripts

Set Parameters RPC

javascript

import {RPCHelper, Utils} from '#tklHelper';
import {Buffer} from "buffer";

function rpc_script({device, params, alarms, logger}) {
let paraDef= {
        app_38: { name: "pwron_delay", field_name: "pwron_delay", unit: "ms", index: 38, type: "uint16le" },
        app_70: {name: "periodUP", field_name: "periodUP", unit: "s",  type: "uint32LE"},
        app_74: {name: "periodRead", field_name: "periodRead", unit: "s", type: "uint32LE"},
        app_110: {name: "cov_temperature", field_name: "cov_temperature", unit: "℃", type: "int16BE",coefficient:0.1,decimal:1},
        app_112: {name: "cov_humidity", field_name: "cov_humidity", unit: "℃", type: "int16BE",coefficient:0.1,decimal:1},
        app_150: {name: "addr", field_name: "addr", unit: "", type: "uint8"},
    }
    let frames=RPCHelper.buildFrame({paraDef:paraDef, params:params});
    let redoBuffer=RPCHelper.redo()
    let dnBuffer=Buffer.alloc(frames.writeBuffer.length+frames.readBuffer.length+redoBuffer.length);
    frames.writeBuffer.copy(dnBuffer,0)
    frames.readBuffer.copy(dnBuffer,frames.writeBuffer.length)
    redoBuffer.copy(dnBuffer,frames.writeBuffer.length+frames.readBuffer.length);
    logger.info("set para")
    let msg=RPCHelper.makeMSG({
        msgType:Utils.msgType.paras,
        device:device,
        dnBuffer:dnBuffer,
        sleepTime:0,
    })
    return [msg]
}

Get Parameters RPC

javascript

import {RPCHelper, Utils} from '#tklHelper';

function rpc_script({device, params, alarms, logger}) {
let paraDef= {
        app_38: { name: "pwron_delay", field_name: "pwron_delay", unit: "ms", index: 38, type: "uint16le" },
        app_70: {name: "periodUP", field_name: "periodUP", unit: "s",  type: "uint32LE"},
        app_74: {name: "periodRead", field_name: "periodRead", unit: "s", type: "uint32LE"},
        app_110: {name: "cov_temperature", field_name: "cov_temperature", unit: "℃", type: "int16BE",coefficient:0.1,decimal:1},
        app_112: {name: "cov_humidity", field_name: "cov_humidity", unit: "℃", type: "int16BE",coefficient:0.1,decimal:1},
        app_150: {name: "addr", field_name: "addr", unit: "", type: "uint8"},
    }
    let frames=RPCHelper.buildFrame({paraDef:paraDef, params:params});
    let msg=RPCHelper.makeMSG({
        msgType:Utils.msgType.paras,
        device:device,
        dnBuffer:frames.readBuffer,
        sleepTime:0,
    })
    return [msg]
}

10. Template Selection

Search for the following template in the ThinkLink platform: AQ3485

Or browse by business type: 21306 / Dual-Channel Temperature Sensor / RS-485 Modbus Cold-Storage Monitoring

11. Additional Notes

Field naming: The humidity field contains refrigerator temperature; temperature contains defrost temperature. These names stem from legacy platform registration.
Manufacturer default communication settings: address 1, baud rate 9600, 8 data bits, no parity, 1 stop bit.
COV thresholds: cov_temperature (app_110) applies to defrost temperature; cov_humidity (app_112) applies to refrigerator temperature. Both are in units of 0.1 °C — a threshold of 10 means 1.0 °C.
Power-on delay: pwron_delay (app_38) is the wait time in milliseconds after KC21 powers on before the first Modbus query is issued.

Network Server

Device

meter

BMS

Industry

1. Sensor Overview

2. Product Features

3. Applications

4. Data Collector

4.1 Hardware Specifications

4.2 Wiring

Power and Communication Interface

Sensor Interface

5. Data Acquisition

5.1 Register Map

6. EdgeBus Model

6.1 EB Configuration

6.2 EB Code

6.3 Notes

7. Thing Model

7.1 Thing Model Information

7.2 Uplink Frame Structure

7.3 Thing Model Script

7.3.1 Telemetry Thing Model Script

8. Third-Party Platform Data Subscription

8.1 MQTT Topic

8.2 Example Payload

9. RPC

9.1 RPC Names

9.2 Parameter Definition

9.3 RPC Scripts

Set Parameters RPC

Get Parameters RPC

10. Template Selection

11. Additional Notes

meter

BMS

Industry

1. Sensor Overview ​

2. Product Features ​

3. Applications ​

4. Data Collector ​

4.1 Hardware Specifications ​

4.2 Wiring ​

Power and Communication Interface ​

Sensor Interface ​

5. Data Acquisition ​

5.1 Register Map ​

6. EdgeBus Model ​

6.1 EB Configuration ​

6.2 EB Code ​

6.3 Notes ​

7. Thing Model ​

7.1 Thing Model Information ​

7.2 Uplink Frame Structure ​

7.3 Thing Model Script ​

7.3.1 Telemetry Thing Model Script ​

8. Third-Party Platform Data Subscription ​

8.1 MQTT Topic ​

8.2 Example Payload ​

9. RPC ​

9.1 RPC Names ​

9.2 Parameter Definition ​

9.3 RPC Scripts ​

Set Parameters RPC ​

Get Parameters RPC ​

10. Template Selection ​

11. Additional Notes ​

1. Sensor Overview

2. Product Features

3. Applications

4. Data Collector

4.1 Hardware Specifications

4.2 Wiring

Power and Communication Interface

Sensor Interface

5. Data Acquisition

5.1 Register Map

6. EdgeBus Model

6.1 EB Configuration

6.2 EB Code

6.3 Notes

7. Thing Model

7.1 Thing Model Information

7.2 Uplink Frame Structure

7.3 Thing Model Script

7.3.1 Telemetry Thing Model Script

8. Third-Party Platform Data Subscription

8.1 MQTT Topic

8.2 Example Payload

9. RPC

9.1 RPC Names

9.2 Parameter Definition

9.3 RPC Scripts

Set Parameters RPC

Get Parameters RPC

10. Template Selection

11. Additional Notes