Table of Contents:

• 1. Introduction
  • 1.1 What is RS485 / UART to NB-IoT Converter
  • 1.2 ​Features
  • 1.3 Specification
  • 1.4 Applications
  • 1.5 Sleep mode and working mode
  • 1.6 Button & LEDs
  • 1.7 BLE connection
  • 1.8 Pin Definitions & Switch
    • 1.8.1 Jumper JP2
    • 1.8.2 BOOT MODE / SW1
    • 1.8.3 Reset Button
• 2. Use RS485-NB to communicate with IoT Server
  • 2.1 Send data to IoT server via NB-IoT network
  • 2.2 Configure Commands to read data
    • 2.2.1 Configure UART settings for RS485 or TTL communication
    • 2.2.2 Configure sensors
    • 2.2.3 Configure read commands for each sampling
    • 2.2.4 Compose the uplink payload
    • 2.2.5 Uplink on demand
    • 2.2.6 Uplink on Interrupt
  • 2.3 ​Payload Types
    • 2.3.1 General Json Format(Type=5)
    • 2.3.2 HEX format Payload(Type=0)
    • 2.3.3 ThingsBoard Payload(Type=3)
    • 2.3.4 ThingSpeak Payload(Type=1)
  • 2.4 Test Uplink and Change Update Interval
  • 2.5 Multi-Samplings and One uplink
  • 2.6 Trggier an uplink by external interrupt
  • 2.7 +3V3 Output
  • 2.8 +5V Output
  • 2.9 Switch Jumper
• 3. Configure RS485-NB
  • 3.1 Configure Methods
  • 3.2 AT Commands Set
• 4. Battery & Power Consumption
• 5. Firmware update
• 6. FAQ
  • 6.1 How can I access t BC660K-GL AT Commands?
  • 6.2 How many RS485-Slave can RS485-NB connects?
  • 6.3 How to Use RS485-NB  to connect to RS232 devices?
  • 6.4 How to judge whether there is a problem with the set COMMAND
    • 6.4.1 Introduce:
    • 6.4.2 Set up PC to monitor RS485 network With Serial tool
    • 6.4.3 With ModRSsim2:
    • 6.4.4 Example – Test the CFGDEV command
    • 6.4.5 Example – Test CMD command sets.
    • 6.4.6 Test with PC
• 7. Order Info
• 8. ​Packing Info
• 9. Support

1. Introduction

1.1 What is RS485 / UART to NB-IoT Converter

The Dragino RS485-NB is a RS485 / UART to NB-IoT Converter for Internet of Things solutions. User can connect RS485 or UART sensor to RS485-NB converter, and configure RS485-NB to periodically read sensor data and upload via NB-IoT network to IoT server.

RS485-NB can interface to RS485 sensor, 3.3v/5v UART sensor or interrupt sensor. RS485-NB provides a 3.3v output and a 5v output to power external sensors. Both output voltages are controllable to minimize the total system power consumption.

RS485-NB supports different uplink methods including MQTT, MQTTs, UDP & TCP for different application requirement, and support uplinks to various IoT Servers.

RS485-NB supports BLE configure and OTA update which make user easy to use.

RS485-NB is IP67 waterproof and powered by 8500mAh Li-SOCI2 battery, it is designed for long-term use up to several years.

RS485-NB has optional built-in SIM card and default IoT server connection version. Which makes it works with simple configuration.

1.2 ​Features

• NB-IoT Bands: B1/B2/B3/B4/B5/B8/B12/B13/B17/B18/B19/B20/B25/B28/B66/B70/B85 @H-FDD
• Ultra-low power consumption
• Support multiply RS485 devices by flexible rules
• Support Modbus protocol
• Support Interrupt uplink
• Supports connecting a UART sensors with 3.3V or 5V
• Multiply Sampling and one uplink
• Support Bluetooth v5.1 remote configure and update firmware
• Uplink via MQTT, MQTTs, TCP, or UDP
• Uplink on periodically
• Downlink to change configure
• 8500mAh Battery for long term use
• Nano SIM card slot for NB-IoT SIM

1.3 Specification

Common DC Characteristics:

• Supply Voltage: 2.5v ~ 3.6v
• Operating Temperature: -40 ~ 85°C

I/O Interface:

• Battery controllable output (2.6v ~ 3.6v depends on battery)
• +5v controllable output
• 1 x RS485 Interface
• 1 x UART Interface , 3.3v or 5v
• 1 x Interrupt or Digital IN/OUT pins
• 1 x I2C Interface
• 1 x one wire interface

NB-IoT Spec:

NB-IoT Module: BC660K-GL

Support Bands:

• B1 @H-FDD: 2100MHz
• B2 @H-FDD: 1900MHz
• B3 @H-FDD: 1800MHz
• B4 @H-FDD: 2100MHz
• B5 @H-FDD: 860MHz
• B8 @H-FDD: 900MHz
• B12 @H-FDD: 720MHz
• B13 @H-FDD: 740MHz
• B17 @H-FDD: 730MHz
• B18 @H-FDD: 870MHz
• B19 @H-FDD: 870MHz
• B20 @H-FDD: 790MHz
• B25 @H-FDD: 1900MHz
• B28 @H-FDD: 750MHz
• B66 @H-FDD: 2000MHz
• B70 @H-FDD: 2000MHz
• B85 @H-FDD: 700MHz

Battery:

• Li/SOCI2 un-chargeable battery
• Capacity: 8500mAh
• Self Discharge: <1% / Year @ 25°C
• Max continuously current: 130mA
• Max boost current: 2A, 1 second

Power Consumption

• STOP Mode: 10uA @ 3.3v
• Max transmit power: 350mA@3.3v

1.4 Applications

• Smart Buildings & Home Automation
• Logistics and Supply Chain Management
• Smart Metering
• Smart Agriculture
• Smart Cities
• Smart Factory

1.5 Sleep mode and working mode

Deep Sleep Mode: Sensor doesn't have any NB-IoT activate. This mode is used for storage and shipping to save battery life.

Working Mode: In this mode, Sensor will work as NB-IoT Sensor to Join NB-IoT network and send out sensor data to server. Between each sampling/tx/rx periodically, sensor will be in IDLE mode), in IDLE mode, sensor has the same power consumption as Deep Sleep mode.

1.6 Button & LEDs

Note: When the device is executing a program, the buttons may become invalid. It is best to press the buttons after the device has completed the program execution.

1.7 BLE connection

RS485-NB support BLE remote configure and firmware update.

BLE can be used to configure the parameter of sensor or see the console output from sensor. BLE will be only activate on below case:

• Press button to send an uplink
• Press button to active device.
• Device Power on or reset.

If there is no activity connection on BLE in 60 seconds, sensor will shut down BLE module to enter low power mode.

1.8 Pin Definitions & Switch

RS485-NB use the mother board which as below.

1.8.1 Jumper JP2

Power on Device when put this jumper.

1.8.2 BOOT MODE / SW1

1) ISP: upgrade mode, device won't have any signal in this mode. but ready for upgrade firmware. LED won't work. Firmware won't run.

2) Flash: work mode, device starts to work and send out console output for further debug

1.8.3 Reset Button

Press to reboot the device.

2. Use RS485-NB to communicate with IoT Server

2.1 Send data to IoT server via NB-IoT network

The RS485-NB is equipped with a NB-IoT module, the pre-loaded firmware in RS485-NB will get environment data from sensors and send the value to local NB-IoT network via the NB-IoT module.  The NB-IoT network will forward this value to IoT server via the protocol defined by RS485-NB.

Below shows the network structure:

There are two version: -GE and -1D version of RS485-NB.

GE Version: This version doesn't include SIM card or point to any IoT server. User needs to use AT Commands to configure below two steps to set RS485-NB send data to IoT server.

• Install NB-IoT SIM card and configure APN. See instruction of Attach Network.

• Set up sensor to point to IoT Server. See instruction of Configure to Connect Different Servers.  

Below shows result of different server as a glance.

1D Version: This version has 1NCE SIM card pre-installed and configure to send value to DataCake. User Just need to select the sensor type in DataCake and Activate RS485-NB and user will be able to see data in DataCake. See here for DataCake Config Instruction.

2.2 Configure Commands to read data

2.2.1 Configure UART settings for RS485 or TTL communication

Example（Soil three-parameter detector）:

Wiring the UART sensor

Set the correct configuration：

AT+BAUDR=9600

AT+PARITY=0

AT+STOPBIT=1

If the sensor needs 5v. Need to move the switch position to 5v and then use the command AT+5VT=30000

Configuration read command：

AT+CFGDEV=FE 03 00 00 00 03 11 C4,0

FE: Station address

03: Function code

00 00：Register start address

00 03：Number of registers

11 04:  Check code

 Use AT+COMMAND1 to set it as a command, and use AT+DATACUT1 to intercept the bytes I need

upload payload：

2.2.2 Configure sensors

Detail of AT+CFGDEV command see AT+CFGDEV detail.

2.2.3 Configure read commands for each sampling

• AT+DATACUT

• AT+SEARCH

• Grab bytes:

• Grab a section.

• Grab different sections.

2.2.4 Compose the uplink payload

1. Battery Info (2 bytes): Battery voltage

2. PAYVER (1 byte): Defined by AT+PAYVER

3. PAYLOAD COUNT (1 byte): Total how many uplinks of this sampling.

4. PAYLOAD# (1 byte): Number of this uplink. (from 0,1,2,3…,to PAYLOAD COUNT)

5. DATA: Valid value: max 6 bytes(US915 version here, Notice*!) for each uplink so each uplink <= 11 bytes. For the last uplink, DATA will might less than 6 bytes

So totally there will be 3 uplinks for this sampling, each uplink includes 6 bytes DATA

DATA1=RETURN1 Valid Value =  20 20 0a 33 90 41

DATA2=1^st ~ 6^th byte of Valid value of RETURN10= 02 aa 05 81 0a 20

DATA3=7^th ~ 11^th bytes of Valid value of RETURN10 = 20 20 20 2d 30

Below are the uplink payloads:

Notice: the Max bytes is according to the max support bytes in different Frequency Bands for lowest SF. As below:

   * For AU915/AS923 bands, if UplinkDwell time=0, max 51 bytes for each uplink ( so 51 -5 = 46 max valid date) 

   * For AU915/AS923 bands, if UplinkDwell time=1, max 11 bytes for each uplink ( so 11 -5 = 6 max valid date). 

   * For US915 band, max 11 bytes for each uplink ( so 11 -5 = 6 max valid date). 

   * For all other bands: max 51 bytes for each uplink  ( so 51 -5 = 46 max valid date). 

   * When AT+DATAUP=1, the maximum number of segments is 15, and the maximum total number of bytes is 1500;

      When AT+DATAUP=1 and AT+ADR=0, the maximum number of bytes of each payload is determined by the DR value. (Since v1.4.0)

• If the data is empty, return to the display（Since v1.4.0）
   

1)  When AT+MOD=1, if the data intercepted by  AT+DATACUT or  AT+MBFUN is empty, it will display NULL, and the payload will be filled with n FFs.

2)  When AT+MOD=2, if the data intercepted by  AT+DATACUT or  AT+MBFUN is empty, it will display NULL, and the payload will be filled with n 00s.

2.2.5 Uplink on demand

2.2.6 Uplink on Interrupt

Put the interrupt sensor between 3.3v_out and GPIO ext.

2.3 ​Payload Types

To meet different server requirement, RS485-NB supports different payload type.

Includes:

• General JSON format payload. (Type=5)

• HEX format Payload. (Type=0)

• ThingSpeak Format. (Type=1)

• ThingsBoard Format. (Type=3)

User can specify the payload type when choose the connection protocol. Example:

AT+PRO=2,0            // Use UDP Connection & hex Payload

AT+PRO=2,5            // Use UDP Connection & Json Payload

AT+PRO=3,5            // Use MQTT Connection & Json Payload

2.3.1 General Json Format(Type=5)

This is the General Json Format. As below:

{"IMEI":866207053462762,"temperature":29.2,"humidity":54.2,"battery":3.27,"signal":24,"Model":S31x-NB, "1":{28.2,48.3,2023/08/10 08:00:37},"2":{28.1,49.1,2023/08/10 07:57:37},"3":{28.1,48.5,2023/08/10 07:54:37},"4":{28.2,48.6,2023/08/10 07:51:37},"5":{28.1,48.9,2023/08/10 07:48:37},"6":{28.2,48.8,2023/08/10 07:45:37},"7":{28.2,48.8,2023/08/10 07:42:37},"8":{28.0,48.8,2023/08/10 07:39:37}}

Notice, from above payload:

• Temperature , Humidity , Battery & Signal are the value at uplink time.

• Json entry 1 ~ 8 are the last 1 ~ 8 sampling data as specify by AT+NOUD=8  Command. Each entry includes (from left to right): Temperature, Humidity, Sampling time.

2.3.2 HEX format Payload(Type=0)

This is the HEX Format. As below:

f86620705346276200640cba16010000000011011801e864d49c2d011a01e364d49925011901eb64d49871011901e564d497bd011a01e664d49709011901e964d49655011a01e864d495a1011a01e864d494ed011801e864d49439

Version:

These bytes include the hardware and software version.

Higher byte: Specify Sensor Model: 0x00 for RS485-NB

Lower byte: Specify the software version: 0x64=100, means firmware version 1.0.0

BAT (Battery Info):

Ex1: 0x0CBA = 3258mV

Signal Strength:

NB-IoT Network signal Strength.

Ex1: 0x16 = 22

0        -113dBm or less

1        -111dBm

2...30 -109dBm... -53dBm

31      -51dBm or greater

99      Not known or not detectable

TimeStamp:   

Unit TimeStamp Example: 64d49439(H) = 1691653177(D)

Put the decimal value into this link(https://www.epochconverter.com/) to get the time.

2.3.3 ThingsBoard Payload(Type=3)

Type3 payload special design for ThingsBoard, it will also configure other default server to ThingsBoard.

{"IMEI":866207053462762,"temperature":29.2,"humidity":54.2,"battery":3.27,"signal":24}

2.3.4 ThingSpeak Payload(Type=1)

This payload meets ThingSpeak platform requirement. It includes only four fields. Form 1~4 are:

Temperature, Humidity, Battery & Signal. This payload type only valid for ThingsSpeak Platform

As below:

field1=27.9&field2=49.9&field3=3.23&field4=28

2.4 Test Uplink and Change Update Interval

By default, Sensor will send uplinks every 2 hours & AT+NOUD=8

User can use below commands to change the uplink interval.

AT+TDC=600        // Set Update Interval to 600s

User can also push the button for more than 1 seconds to activate an uplink.

2.5 Multi-Samplings and One uplink

To save battery life, RS485-NB will sample temperature & humidity data every 15 minutes and send one uplink every 2 hours. So each uplink it will include 8 stored data + 1 real-time data. They are defined by:

• AT+TR=900        // The unit is seconds, and the default is to record data once every 900 seconds (15 minutes, the minimum can be set to 180 seconds)

• AT+NOUD=8     //  The device uploads 8 sets of recorded data by default. Up to 32 sets of record data can be uploaded.

The diagram below explains the relationship between TR, NOUD, and TDC more clearly:

2.6 Trggier an uplink by external interrupt

RS485-NB has an external trigger interrupt function. Users can use the PB15 pin to trigger the upload of data packets.

AT command:

• AT+INTMOD         // Set the trigger interrupt mode

• AT+INTMOD=0    // Disable Interrupt

• AT+INTMOD=1    // Trigger by rising and falling edge

• AT+INTMOD=2    // Trigger by falling edge

• AT+INTMOD=3    // Trigger by rising edge

2.7 +3V3 Output

2.8 +5V Output

2.9 Switch Jumper

3. Configure RS485-NB

3.1 Configure Methods

RS485-NB supports below configure method:

• AT Command via Bluetooth Connection (Recommended): BLE Configure Instruction.

• AT Command via UART Connection : See UART Connection.

3.2 AT Commands Set

AT+<CMD>?           : Help on <CMD>

AT+<CMD>                      : Run <CMD>

AT+<CMD>=<value>      : Set the value

AT+<CMD>=?          : Get the value

General Commands       

AT                    : Attention        

AT?                  : Short Help      

ATZ                 : MCU Reset     

AT+TDC          : Application Data Transmission Interval

AT+CFG          : Print all configurations

AT+CFGMOD           : Working mode selection

AT+DEUI                  : Get or set the Device ID

AT+INTMOD            : Set the trigger interrupt mode

AT+5VT           : Set extend the time of 5V power   

AT+PRO          : Choose agreement

AT+RXDL        : Extend the sending and receiving time

AT+DNSCFG   : Get or Set DNS Server

AT+GETSENSORVALUE   : Returns the current sensor measurement

AT+NOUD  : Get or Set the number of data to be uploaded

AT+CDP     : Read or Clear cached data

AT+SHTEMP:   Get or Set alarm of temp

AT+SHHUM:   Get or Set alarm of moisture

AT+SERVADDR :   Server Address

UDP Management

AT+CFM  :    Upload confirmation mode (only valid for UDP)

MQTT Management

AT+CLIENT               : Get or Set MQTT client

AT+UNAME              : Get or Set MQTT Username

AT+PWD                  : Get or Set MQTT password

AT+PUBTOPIC          : Get or Set MQTT publish topic

AT+SUBTOPIC          : Get or Set MQTT subscription topic

Information           

AT+FDR              : Factory Data Reset

AT+PWORD        : Serial Access Password

AT+LDATA           : Get the last upload data

AT+CDP               : Read or Clear cached data

4. Battery & Power Consumption

RS485-NB use ER26500 + SPC1520 battery pack. See below link for detail information about the battery info and how to replace.

Battery Info & Power Consumption Analyze .

5. Firmware update

User can change device firmware to::

• Update with new features.

• Fix bugs. 

Firmware and changelog can be downloaded from : Firmware download link

Methods to Update Firmware:

• (Recommended way) OTA firmware update via BLE: Instruction.

• Update through UART TTL interface : Instruction.

6. FAQ

6.1 How can I access t BC660K-GL AT Commands?

User can access to BC660K-GL directly and send AT Commands.

See BC660K-GL AT Command set

6.2 How many RS485-Slave can RS485-NB connects?

6.3 How to Use RS485-NB  to connect to RS232 devices?

Use RS485-LB or RS485-LN to connect to RS232 devices. - DRAGINO

6.4 How to judge whether there is a problem with the set COMMAND

6.4.1 Introduce:

Users can use below the structure to fast debug the communication between RS485-LB and RS485-LN. The principle is to put the PC in the RS485 network and sniff the packet between Modbus MTU and RS485-LB/LN.  We can use this way to:

1. Test if Modbus-MTU works with PC commands.
2. Check if RS485-LN sent the expected command to Mobus-MTU
3. Check if Modbus-MTU return back the expected result to RS485-LN.
4. If both b) and c) has issue, we can compare PC's output and RS485-LN output.

Example Connection: 

6.4.2 Set up PC to monitor RS485 network With Serial tool

Note: Receive and send set to hex mode

6.4.3 With ModRSsim2:

(1) Select serial port MODBUS RS-232

(2) Click the serial port icon

(3) After selecting the correct serial port and baud rate, click ok

(4) Click the comms.

Run RS485-LN/BL command and monitor if it is correct.

6.4.4 Example – Test the CFGDEV command

RS485-LN sent below command:

AT+CFGDEV=01 03 20 00 01 85 c0,1 to RS485 network, and PC is able to get this command and return commands from MTU to show in the serial tool.

We can see the output from the Serial port tool to analyze. And check if they are expected result.

We can also use ModRSsim2 to see the output.

6.4.5 Example – Test CMD command sets.

Run AT+SENSORVALUE=1 to test the CMD commands set in RS485-LN.

Serial port tool:

ModRSsim2:

6.4.6 Test with PC

If there is still have problem to set up correctly the commands between RS485-LN and MTU. User can test the correct RS485 command set in PC and compare with the RS485 command sent out via RS485-LN. as long as both commands are the same, the MTU should return correct result.

Or User can send the working commands set in PC serial tool to Dragino Support to check what should be configured in RS485-LN.

Connection method：

Link situation:

7. Order Info

Part Number: RS485-NB-XX

XX: 

• GE: General version ( Exclude SIM card)

• 1D: with 1NCE* 10 years 500MB SIM card and Pre-configure to DataCake server

YY: The grand connector hole size

• M12: M12 hole

• M16: M16 hole

8. ​Packing Info

Package Includes:

• RS485-NB NB-IoT Sensor Node x 1

• External antenna x 1

Dimension and weight:

• Device Size: 13.0 x 5 x 4.5 cm

• Device Weight: 150g

• Package Size / pcs : 14.0 x 8x 5 cm

• Weight / pcs : 180g

9. Support

• Support is provided Monday to Friday, from 09:00 to 18:00 GMT+8. Due to different timezones we cannot offer live support. However, your questions will be answered as soon as possible in the before-mentioned schedule.

• Provide as much information as possible regarding your enquiry (product models, accurately describe your problem and steps to replicate it etc) and send a mail to Support@dragino.cc.