RS485-BL – Waterproof RS485 to LoRaWAN Converter

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

26

)))

27

28

(((

29

RS485-BL can interface to RS485 sensor, 3.3v/5v UART sensor or interrupt sensor. RS485-BL 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-BL is IP67 **waterproof** and powered by **8500mAh Li-SOCI2 battery**, it is designed for long term use for several years.

)))

(((

RS485-BL runs standard **LoRaWAN 1.0.3 in Class A**. It can reach long transfer range and easy to integrate with LoRaWAN compatible gateway and IoT server.

)))

(((

For data uplink, RS485-BL sends user-defined commands to RS485 devices and gets the return from the RS485 devices. RS485-BL will process these returns data according to user-define rules to get the final payload and upload to LoRaWAN server.

)))

(((

For data downlink, RS485-BL runs in LoRaWAN Class A. When there is downlink commands from LoRaWAN server, RS485-BL will forward the commands from LoRaWAN server to RS485 devices.

)))

(((

Each RS485-BL pre-load with a set of unique keys for LoRaWAN registration, register these keys to LoRaWAN server and it will auto connect after power on.

50

)))

51

52

[[image:1652953304999-717.png||height="424" width="733"]]

53

54

== 1.2 Specifications ==

**Hardware System:**

* STM32L072CZT6 MCU

* SX1276/78 Wireless Chip

60

* Power Consumption (exclude RS485 device):

** Idle: 6uA@3.3v

*

** 20dB Transmit: 130mA@3.3v

65

66

**Interface for Model:**

67

68

* 1 x RS485 Interface

69

* 1 x TTL Serial , 3.3v or 5v.

70

* 1 x I2C Interface, 3.3v or 5v.

71

* 1 x one wire interface

72

* 1 x Interrupt Interface

73

* 1 x Controllable 5V output, max

**LoRa Spec:**

* Frequency Range:

** Band 1 (HF): 862 ~~ 1020 Mhz

79

** Band 2 (LF): 410 ~~ 528 Mhz

80

* 168 dB maximum link budget.

81

* +20 dBm - 100 mW constant RF output vs.

82

* Programmable bit rate up to 300 kbps.

83

* High sensitivity: down to -148 dBm.

84

* Bullet-proof front end: IIP3 = -12.5 dBm.

85

* Excellent blocking immunity.

86

* Fully integrated synthesizer with a resolution of 61 Hz.

87

* LoRa modulation.

88

* Built-in bit synchronizer for clock recovery.

89

* Preamble detection.

90

* 127 dB Dynamic Range RSSI.

91

* Automatic RF Sense and CAD with ultra-fast AFC.

== 1.3 Features ==

* LoRaWAN Class A & Class C protocol (default Class A)

96

* Frequency Bands: CN470/EU433/KR920/US915/EU868/AS923/AU915/IN865/RU864

97

* AT Commands to change parameters

98

* Remote configure parameters via LoRaWAN Downlink

99

* Firmware upgradable via program port

100

* Support multiply RS485 devices by flexible rules

101

* Support Modbus protocol

102

* Support Interrupt uplink

103

104

== 1.4 Applications ==

105

106

* Smart Buildings & Home Automation

107

* Logistics and Supply Chain Management

* Smart Metering

* Smart Agriculture

* Smart Cities

* Smart Factory

== 1.5 Firmware Change log ==

114

115

[[RS485-BL Image files – Download link and Change log>>url:http://www.dragino.com/downloads/index.php?dir=LoRa_End_Node/RS485-BL/Firmware/||style="background-color: rgb(255, 255, 255);"]]

116

117

== 1.6 Hardware Change log ==

(((

v1.4

)))

(((

~1. Change Power IC to TPS22916

)))

(((

v1.3

)))

(((

~1. Change JP3 from KF350-8P to KF350-11P, Add one extra interface for I2C and one extra interface for one-wire

)))

(((

v1.2

)))

(((

Release version

)))

= 2. Pin mapping and Power ON Device =

146

147

(((

148

The RS485-BL is powered on by 8500mAh battery. To save battery life, RS485-BL is shipped with power off. User can put the jumper to power on RS485-BL.

149

)))

150

151

[[image:1652953055962-143.png||height="387" width="728"]]

152

153

154

The Left TXD and RXD are TTL interface for external sensor. TTL level is controlled by 3.3/5v Jumper.

155

156

= 3. Operation Mode =

157

158

== 3.1 How it works? ==

159

160

(((

161

The RS485-BL is configured as LoRaWAN OTAA Class A mode by default. It has OTAA keys to join network. To connect a local LoRaWAN network, user just need to input the OTAA keys in the network server and power on the RS485-BL. It will auto join the network via OTAA.

162

)))

163

164

== 3.2 Example to join LoRaWAN network ==

165

166

Here shows an example for how to join the TTN V3 Network. Below is the network structure, we use [[LG308>>url:http://www.dragino.com/products/lora-lorawan-gateway/item/140-lg308.html]] as LoRaWAN gateway here.

167

168

[[image:1652953414711-647.png||height="337" width="723"]]

169

170

(((

171

The RS485-BL in this example connected to two RS485 devices for demonstration, user can connect to other RS485 devices via the same method.

)))

(((

The LG308 is already set to connect to [[TTN V3 network >>url:https://www.thethingsnetwork.org/]]. So what we need to now is only configure the TTN V3:

)))

(((

**Step 1**: Create a device in TTN V3 with the OTAA keys from RS485-BL.

)))

(((

Each RS485-BL is shipped with a sticker with unique device EUI:

184

)))

185

186

[[image:1652953462722-299.png]]

187

188

(((

189

User can enter this key in their LoRaWAN Server portal. Below is TTN V3 screen shot:

)))

(((

Add APP EUI in the application.

)))

[[image:image-20220519174512-1.png]]

200

201

[[image:image-20220519174512-2.png||height="328" width="731"]]

202

203

[[image:image-20220519174512-3.png||height="556" width="724"]]

204

205

[[image:image-20220519174512-4.png]]

206

207

You can also choose to create the device manually.

208

209

[[image:1652953542269-423.png||height="710" width="723"]]

210

211

Add APP KEY and DEV EUI

212

213

[[image:1652953553383-907.png||height="514" width="724"]]

(((

**Step 2**: Power on RS485-BL and it will auto join to the TTN V3 network. After join success, it will start to upload message to TTN V3 and user can see in the panel.

218

)))

219

220

[[image:1652953568895-172.png||height="232" width="724"]]

221

222

== 3.3 Configure Commands to read data ==

223

224

(((

225

There are plenty of RS485 and TTL level devices in the market and each device has different command to read the valid data. To support these devices in flexible, RS485-BL supports flexible command set. User can use [[AT Commands or LoRaWAN Downlink>>path:#AT_COMMAND]] Command to configure how RS485-BL should read the sensor and how to handle the return from RS485 or TTL sensors.

226

)))

227

228

=== 3.3.1 onfigure UART settings for RS485 or TTL communication ===

229

230

RS485-BL can connect to either RS485 sensors or TTL sensor. User need to specify what type of sensor need to connect.

231

232

**~1. RS485-MODBUS mode:**

233

234

AT+MOD=1 ~/~/ Support RS485-MODBUS type sensors. User can connect multiply RS485 , Modbus sensors to the A / B pins.

**2. TTL mode:**

AT+MOD=2 ~/~/ Support TTL Level sensors, User can connect one TTL Sensor to the TXD/RXD/GND pins.

239

240

RS485-BL default UART settings is **9600, no parity, stop bit 1**. If the sensor has a different settings, user can change the RS485-BL setting to match.

241

242

(% border="1" style="background-color:#ffffcc; color:green; width:795px" %)

243

|(((

244

**AT Commands**

245

)))|(% style="width:285px" %)(((

246

**Description**

247

)))|(% style="width:347px" %)(((

**Example**

)))

|(((

AT+BAUDR

)))|(% style="width:285px" %)(((

253

Set the baud rate (for RS485 connection). Default Value is: 9600.

254

)))|(% style="width:347px" %)(((

(((

AT+BAUDR=9600

)))

(((

Options: (1200,2400,4800,14400,19200,115200)

)))

)))

|(((

AT+PARITY

)))|(% style="width:285px" %)(((

266

(((

267

Set UART parity (for RS485 connection)

)))

(((

Default Value is: no parity.

272

)))

273

)))|(% style="width:347px" %)(((

(((

AT+PARITY=0

)))

(((

Option: 0: no parity, 1: odd parity, 2: even parity

)))

)))

|(((

AT+STOPBIT

)))|(% style="width:285px" %)(((

285

(((

286

Set serial stopbit (for RS485 connection)

)))

(((

Default Value is: 1bit.

291

)))

292

)))|(% style="width:347px" %)(((

293

(((

294

AT+STOPBIT=0 for 1bit

)))

(((

AT+STOPBIT=1 for 1.5 bit

)))

(((

AT+STOPBIT=2 for 2 bits

)))

)))

=== 3.3.2 Configure sensors ===

307

308

(((

309

Some sensors might need to configure before normal operation. User can configure such sensor via PC or through RS485-BL AT Commands (% style="color:#4f81bd" %)**AT+CFGDEV**.

)))

(((

When user issue an (% style="color:#4f81bd" %)**AT+CFGDEV**(%%) command, Each (% style="color:#4f81bd" %)**AT+CFGDEV**(%%) equals to send a command to the RS485 or TTL sensors. This command will only run when user input it and won’t run during each sampling.

314

)))

315

316

(% border="1" style="background-color:#ffffcc; color:green; width:806px" %)

317

|**AT Commands**|(% style="width:418px" %)**Description**|(% style="width:256px" %)**Example**

318

|AT+CFGDEV|(% style="width:418px" %)(((

319

This command is used to configure the RS485/TTL devices; they won’t be used during sampling.

320

321

AT+CFGDEV=xx xx xx xx xx xx xx xx xx xx xx xx,

322

323

mm: 0: no CRC, 1: add CRC-16/MODBUS in the end of this command

324

)))|(% style="width:256px" %)AT+CFGDEV=xx xx xx xx xx xx xx xx xx xx xx xx,m

325

326

Detail of AT+CFGDEV command see [[AT+CFGDEV detail>>path:#AT_CFGDEV]].

327

328

=== 3.3.3 Configure read commands for each sampling ===

329

330

(((

331

RS485-BL is a battery powered device; it will sleep most of time. And wake up on each period and read RS485 / TTL sensor data and uplink.

)))

(((

During each sampling, we need to confirm what commands we need to send to the sensors to read data. After the RS485/TTL sensors send back the value, it normally includes some bytes and we only need a few from them for a shorten payload.

)))

(((

To save the LoRaWAN network bandwidth, we might need to read data from different sensors and combine their valid value into a short payload.

)))

(((

This section describes how to achieve above goals.

)))

(((

During each sampling, the RS485-BL can support 15 commands to read sensors. And combine the return to one or several uplink payloads.

)))

(((

**Command from RS485-BL to Sensor:**

)))

(((

RS485-BL can send out pre-set max 15 strings via **AT+COMMAD1**, **ATCOMMAND2**,…, to **AT+COMMANDF** . All commands are of same grammar.

)))

(((

**Handle return from sensors to RS485-BL**:

)))

(((

After RS485-BL send out a string to sensor, RS485-BL will wait for the return from RS485 or TTL sensor. And user can specify how to handle the return, by **AT+DATACUT or AT+SEARCH commands**

)))

* (((

**AT+DATACUT**

)))

(((

When the return value from sensor have fix length and we know which position the valid value we should get, we can use AT+DATACUT command.

)))

* (((

**AT+SEARCH**

)))

(((

When the return value from sensor is dynamic length and we are not sure which bytes the valid data is, instead, we know what value the valid value following. We can use AT+SEARCH to search the valid value in the return string.

)))

(((

**Define wait timeout:**

)))

(((

Some RS485 device might has longer delay on reply, so user can use AT+CMDDL to set the timeout for getting reply after the RS485 command is sent. For example, AT+CMDDL1=1000 to send the open time to 1000ms

)))

(((

After we got the valid value from each RS485 commands, we need to combine them together with the command **AT+DATAUP**.

)))

**Examples:**

Below are examples for the how above AT Commands works.

397

398

**AT+COMMANDx : **This command will be sent to RS485/TTL devices during each sampling, Max command length is 14 bytes. The grammar is:

399

400

(% border="1" class="table-bordered" style="background-color:#4f81bd; color:white; width:501px" %)

401

|(% style="width:498px" %)(((

402

**AT+COMMANDx=xx xx xx xx xx xx xx xx xx xx xx xx,m**

403

404

**xx xx xx xx xx xx xx xx xx xx xx xx: The RS485 command to be sent**

405

406

**m: 0: no CRC, 1: add CRC-16/MODBUS in the end of this command**

407

)))

408

409

For example, if we have a RS485 sensor. The command to get sensor value is: 01 03 0B B8 00 02 46 0A. Where 01 03 0B B8 00 02 is the Modbus command to read the register 0B B8 where stored the sensor value. The 46 0A is the CRC-16/MODBUS which calculate manually.

410

411

In the RS485-BL, we should use this command AT+COMMAND1=01 03 0B B8 00 02,1 for the same.

412

413

**AT+SEARCHx**: This command defines how to handle the return from AT+COMMANDx.

414

415

(% border="1" class="table-bordered" style="background-color:#4f81bd; color:white; width:580px" %)

416

|(% style="width:577px" %)(((

417

**AT+SEARCHx=aa,xx xx xx xx xx**

418

419

* **aa: 1: prefix match mode; 2: prefix and suffix match mode**

420

* **xx xx xx xx xx: match string. Max 5 bytes for prefix and 5 bytes for suffix**

)))

**Examples:**

1. For a return string from AT+COMMAND1: 16 0c 1e 56 34 2e 30 58 5f 36 41 30 31 00 49

426

427

If we set AT+SEARCH1=1,1E 56 34. (max 5 bytes for prefix)

428

429

The valid data will be all bytes after 1E 56 34 , so it is (% style="background-color:yellow" %)**2e 30 58 5f 36 41 30 31 00 49**

430

431

[[image:1653271044481-711.png]]

432

433

1. For a return string from AT+COMMAND1: 16 0c 1e 56 34 2e 30 58 5f 36 41 30 31 00 49

434

435

If we set AT+SEARCH1=2, 1E 56 34+31 00 49

436

437

Device will search the bytes between 1E 56 34 and 31 00 49. So it is(% style="background-color:yellow" %) **2e 30 58 5f 36 41 30**

438

439

[[image:1653271276735-972.png]]

440

441

**AT+DATACUTx : **This command defines how to handle the return from AT+COMMANDx, max return length is 45 bytes.

442

443

(% style="background-color:#4f81bd; color:white; width:729px" %)

444

|(% style="width:726px" %)(((

445

**AT+DATACUTx=a,b,c**

446

447

* **a: length for the return of AT+COMMAND**

448

* **b:1: grab valid value by byte, max 6 bytes. 2: grab valid value by bytes section, max 3 sections.**

449

* **c: define the position for valid value. **

)))

Examples:

* Grab bytes:

[[image:1653271581490-837.png||height="313" width="722"]]

* Grab a section.

[[image:1653271648378-342.png||height="326" width="720"]]

461

462

* Grab different sections.

463

464

[[image:1653271657255-576.png||height="305" width="730"]]

465

466

(((

467

(% style="color:red" %)**Note:**

)))

(((

AT+SEARCHx and AT+DATACUTx can be used together, if both commands are set, RS485-BL will first process AT+SEARCHx on the return string and get a temporary string, and then process AT+DATACUTx on this temporary string to get the final payload. In this case, AT+DATACUTx need to set to format AT+DATACUTx=0,xx,xx where the return bytes set to 0.

)))

(((

**Example:**

)))

(((

(% style="color:red" %)AT+COMMAND1=11 01 1E D0,0

)))

(((

(% style="color:red" %)AT+SEARCH1=1,1E 56 34

)))

(((

(% style="color:red" %)AT+DATACUT1=0,2,1~~5

)))

(((

(% style="color:red" %)Return string from AT+COMMAND1: 16 0c 1e 56 34 2e 30 58 5f 36 41 30 31 00 49

)))

(((

(% style="color:red" %)String after SEARCH command: 2e 30 58 5f 36 41 30 31 00 49

)))

(((

(% style="color:red" %)Valid payload after DataCUT command: 2e 30 58 5f 36

500

)))

501

502

[[image:1653271763403-806.png]]

503

504

=== 3.3.4 Compose the uplink payload ===

505

506

(((

507

Through AT+COMMANDx and AT+DATACUTx we got valid value from each RS485 commands, Assume these valid value are RETURN1, RETURN2, .., to RETURNx. The next step is how to compose the LoRa Uplink Payload by these RETURNs. The command is **AT+DATAUP.**

)))

(((

(% style="color:#4f81bd" %)**Examples: AT+DATAUP=0**

)))

(((

Compose the uplink payload with value returns in sequence and send with (% style="color:red" %)**A SIGNLE UPLINK**.

)))

(((

Final Payload is

)))

(((

(% style="color:#4f81bd" %)Battery Info+PAYVER + VALID Value from RETURN1 + Valid Value from RETURN2 + … + RETURNx

)))

(((

Where PAYVER is defined by AT+PAYVER, below is an example screen shot.

528

)))

529

530

[[image:1653272787040-634.png||height="515" width="719"]]

531

532

(((

533

(% style="color:#4f81bd" %)**Examples: AT+DATAUP=1**

)))

(((

Compose the uplink payload with value returns in sequence and send with (% style="color:red" %)**Multiply UPLINKs**.

)))

(((

Final Payload is

)))

(((

(% style="color:#4f81bd" %)Battery Info+PAYVER + PAYLOAD COUNT + PAYLOAD# + DATA

)))

1. (((

Battery Info (2 bytes): Battery voltage

550

)))

551

1. (((

552

PAYVER (1 byte): Defined by AT+PAYVER

553

)))

554

1. (((

555

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

556

)))

557

1. (((

558

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

559

)))

560

1. (((

561

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

562

)))

563

564

[[image:1653272817147-600.png||height="437" width="717"]]

565

566

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

567

568

DATA1=RETURN1 Valid Value = (% style="background-color:#4f81bd; color:white" %) 20 20 0a 33 90 41

569

570

DATA2=1^^st^^ ~~ 6^^th^^ byte of Valid value of RETURN10= (% style="background-color:#4f81bd; color:white" %)02 aa 05 81 0a 20

571

572

DATA3=7^^th^^ ~~ 11^^th^^ bytes of Valid value of RETURN10 =(% style="background-color:#4f81bd; color:white" %) 20 20 20 2d 30

573

574

Below are the uplink payloads:

575

576

[[image:1653272901032-107.png]]

577

578

(% style="color:red" %)Notice: the Max bytes is according to the max support bytes in different Frequency Bands for lowest SF. As below:

579

580

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

581

582

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

583

584

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

585

586

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

587

588

=== 3.3.5 Uplink on demand ===

589

590

(((

591

Except uplink periodically, RS485-BL is able to uplink on demand. The server sends downlink command to RS485-BL and RS485 will uplink data base on the command.

)))

(((

Downlink control command:

)))

(((

**0x08 command**: Poll an uplink with current command set in RS485-BL.

)))

(((

**0xA8 command**: Send a command to RS485-BL and uplink the output from sensors.

604

)))

605

606

=== 3.3.6 Uplink on Interrupt ===

607

608

Put the interrupt sensor between 3.3v_out and GPIO ext.

609

610

[[image:1653273818896-432.png]]

611

612

(((

613

AT+INTMOD=0 Disable Interrupt

)))

(((

AT+INTMOD=1 Interrupt trigger by rising or falling edge.

)))

(((

AT+INTMOD=2 Interrupt trigger by falling edge. ( Default Value)

)))

(((

AT+INTMOD=3 Interrupt trigger by rising edge.

626

)))

627

628

== 3.4 Uplink Payload ==

629

630

(% border="1" style="background-color:#4f81bd; color:white; width:850px" %)

631

|**Size(bytes)**|(% style="width:130px" %)**2**|(% style="width:93px" %)**1**|(% style="width:509px" %)**Length depends on the return from the commands**

632

|Value|(% style="width:130px" %)(((

(((

Battery(mV)

)))

(((

&

)))

(((

Interrupt _Flag

)))

)))|(% style="width:93px" %)(((

PAYLOAD_VER

)))|(% style="width:509px" %)If the valid payload is too long and exceed the maximum support payload length in server, server will show payload not provided in the LoRaWAN server.

649

650

Below is the decoder for the first 3 bytes. The rest bytes are dynamic depends on different RS485 sensors.

651

652

(((

653

function Decoder(bytes, port) {

)))

(((

~/~/Payload Formats of RS485-BL Deceive

)))

(((

return {

)))

(((

~/~/Battery,units:V

)))

(((

BatV:((bytes[0]<<8 | bytes[1])&0x7fff)/1000,

)))

(((

~/~/GPIO_EXTI

)))

(((

EXTI_Trigger:(bytes[0] & 0x80)? "TRUE":"FALSE",

)))

(((

~/~/payload of version

)))

(((

Pay_ver:bytes[2],

)))

(((

};

)))

(((

}

)))

(((

TTN V3 uplink screen shot.

698

)))

699

700

[[image:1653274001211-372.png||height="192" width="732"]]

701

702

== 3.5 Configure RS485-BL via AT or Downlink ==

703

704

User can configure RS485-BL via [[AT Commands >>path:#_Using_the_AT]]or LoRaWAN Downlink Commands

705

706

There are two kinds of Commands:

707

708

* **Common Commands**: They should be available for each sensor, such as: change uplink interval, reset device. For firmware v1.3, user can find what common commands it supports: http:~/~/wiki.dragino.com/index.php?title=End_Device_AT_Commands_and_Downlink_Commands

709

710

* **Sensor Related Commands**: These commands are special designed for RS485-BL. User can see these commands below:

1.

11.

111. Common Commands:

715

716

They should be available for each of Dragino Sensors, such as: change uplink interval, reset device. For firmware v1.3, user can find what common commands it supports: [[http:~~/~~/wiki.dragino.com/index.php?title=End_Device_AT_Commands_and_Downlink_Commands>>url:http://wiki.dragino.com/index.php?title=End_Device_AT_Commands_and_Downlink_Commands]]

1.

11.

111. Sensor related commands:

722

723

==== Choose Device Type (RS485 or TTL) ====

724

725

RS485-BL can connect to either RS485 sensors or TTL sensor. User need to specify what type of sensor need to connect.

* AT Command

**AT+MOD=1** ~/~/ Set to support RS485-MODBUS type sensors. User can connect multiply RS485 , Modbus sensors to the A / B pins.

730

731

**AT+MOD=2** ~/~/ Set to support TTL Level sensors, User can connect one TTL Sensor to the TXD/RXD/GND pins.

* Downlink Payload

**0A aa** à same as AT+MOD=aa

==== [[RS485 Debug Command>>path:#downlink_A8]] (AT+CFGDEV) ====

741

742

This command is used to configure the RS485 or TTL sensors; they won’t be used during sampling.

* AT Command

AT+CFGDEV=xx xx xx xx xx xx xx xx xx xx xx xx,m

747

748

m: 0: no CRC; 1: add CRC-16/MODBUS in the end of this command.

* Downlink Payload

Format: A8 MM NN XX XX XX XX YY

Where:

* MM: 1: add CRC-16/MODBUS ; 0: no CRC

759

* NN: The length of RS485 command

760

* XX XX XX XX: RS485 command total NN bytes

761

* YY: How many bytes will be uplink from the return of this RS485 command, if YY=0, RS485-BL will execute the downlink command without uplink; if YY>0, RS485-BL will uplink total YY bytes from the output of this RS485 command

**Example 1:**

To connect a Modbus Alarm with below commands.

766

767

* The command to active alarm is: 0A 05 00 04 00 01 4C B0. Where 0A 05 00 04 00 01 is the Modbus command to read the register 00 40 where stored the DI status. The 4C B0 is the CRC-16/MODBUS which calculate manually.

768

769

* The command to deactivate alarm is: 0A 05 00 04 00 00 8D 70. Where 0A 05 00 04 00 00 is the Modbus command to read the register 00 40 where stored the DI status. The 8D 70 is the CRC-16/MODBUS which calculate manually.

770

771

So if user want to use downlink command to control to RS485 Alarm, he can use:

772

773

**A8 01 06 0A 05 00 04 00 01 00**: to activate the RS485 Alarm

774

775

**A8 01 06 0A 05 00 04 00 00 00**: to deactivate the RS485 Alarm

776

777

A8 is type code and 01 means add CRC-16/MODBUS at the end, the 3^^rd^^ byte is 06, means the next 6 bytes are the command to be sent to the RS485 network, the final byte 00 means this command don’t need to acquire output.

**Example 2:**

Check TTL Sensor return:

783

784

[[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image024.png]]

==== Set Payload version ====

790

791

This is the first byte of the uplink payload. RS485-BL can connect to different sensors. User can set the PAYVER field to tell server how to decode the current payload.

* AT Command:

AT+PAYVER: Set PAYVER field = 1

* Downlink Payload:

0xAE 01 à Set PAYVER field = 0x01

801

802

0xAE 0F à Set PAYVER field = 0x0F

803

804

805

==== Set RS485 Sampling Commands ====

806

807

AT+COMMANDx, AT+DATACUTx and AT+SEARCHx

808

809

These three commands are used to configure how the RS485-BL polling data from Modbus device. Detail of usage please see : [[polling RS485 device>>path:#polling_485]].

* AT Command:

AT+COMMANDx: Configure RS485 read command to sensor.

815

816

AT+DATACUTx: Configure how to handle return from RS485 devices.

817

818

AT+SEARCHx: Configure search command

* Downlink Payload:

0xAF downlink command can be used to set AT+COMMANDx or AT+DATACUTx.

824

825

Note: if user use AT+COMMANDx to add a new command, he also need to send AT+DATACUTx downlink.

826

827

Format: AF MM NN LL XX XX XX XX YY

Where:

* MM: the ATCOMMAND or AT+DATACUT to be set. Value from 01 ~~ 0F,

832

* NN: 0: no CRC; 1: add CRC-16/MODBUS ; 2: set the AT+DATACUT value.

833

* LL: The length of AT+COMMAND or AT+DATACUT command

834

* XX XX XX XX: AT+COMMAND or AT+DATACUT command

835

* YY: If YY=0, RS485-BL will execute the downlink command without uplink; if YY=1, RS485-BL will execute an uplink after got this command.

Example:

**AF 03 01 06 0A 05 00 04 00 01 00**: Same as AT+COMMAND3=0A 05 00 04 00 01,1

840

841

**AF 03 02 06 10 01 05 06 09 0A 00**: Same as AT+DATACUT3=**16**,**1**,**5+6+9+10**

842

843

**AF 03 02 06 0B 02 05 07 08 0A 00**: Same as AT+DATACUT3=**11**,**2**,**5~~7+8~~10**

844

845

846

0xAB downlink command can be used for set AT+SEARCHx

847

848

Example: **AB aa 01 03 xx xx xx** (03 here means there are total 3 bytes after 03) So

849

850

* AB aa 01 03 xx xx xx same as AT+SEARCHaa=1,xx xx xx

851

* AB aa 02 03 xx xx xx 02 yy yy(03 means there are 3 bytes after 03, they are xx xx xx;02 means there are 2 bytes after 02, they are yy yy) so the commands

852

853

**AB aa 02 03 xx xx xx 02 yy yy** same as **AT+SEARCHaa=2,xx xx xx+yy yy**

854

855

856

==== Fast command to handle MODBUS device ====

857

858

AT+MBFUN is valid since v1.3 firmware version. The command is for fast configure to read Modbus devices. It is only valid for the devices which follow the [[MODBUS-RTU protocol>>url:https://www.modbustools.com/modbus.html]].

859

860

This command is valid since v1.3 firmware version

861

862

863

AT+MBFUN has only two value:

864

865

* AT+MBFUN=1: Enable Modbus reading. And get response base on the MODBUS return

866

867

AT+MBFUN=1, device can auto read the Modbus function code: 01, 02, 03 or 04. AT+MBFUN has lower priority vs AT+DATACUT command. If AT+DATACUT command is configured, AT+MBFUN will be ignore.

868

869

* AT+MBFUN=0: Disable Modbus fast reading.

Example:

* AT+MBFUN=1 and AT+DATACUT1/AT+DATACUT2 are not configure (0,0,0).

874

* AT+COMMAND1= 01 03 00 10 00 08,1 ~-~-> read slave address 01 , function code 03, start address 00 01, quantity of registers 00 08.

875

* AT+COMMAND2= 01 02 00 40 00 10,1 ~-~-> read slave address 01 , function code 02, start address 00 40, quantity of inputs 00 10.

876

877

[[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image025.png]]

878

879

880

[[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image026.png]]

* Downlink Commands:

A9 aa -à Same as AT+MBFUN=aa

886

887

888

==== RS485 command timeout ====

889

890

Some Modbus device has slow action to send replies. This command is used to configure the RS485-BL to use longer time to wait for their action.

891

892

Default value: 0, range: 0 ~~ 5 seconds

* AT Command:

AT+CMDDLaa=hex(bb cc)

Example:

**AT+CMDDL1=1000** to send the open time to 1000ms

* Downlink Payload:

0x AA aa bb cc

Same as: AT+CMDDLaa=hex(bb cc)

Example:

0xAA 01 03 E8 à Same as **AT+CMDDL1=1000 ms**

913

914

915

==== [[Uplink>>path:#downlink_A8]] payload mode ====

916

917

Define to use one uplink or multiple uplinks for the sampling.

918

919

The use of this command please see: [[Compose Uplink payload>>path:#DataUP]]

* AT Command:

AT+DATAUP=0

AT+DATAUP=1

* Downlink Payload:

0xAD 00 à Same as AT+DATAUP=0

931

932

0xAD 01 à Same as AT+DATAUP=1

933

934

935

==== Manually trigger an Uplink ====

936

937

Ask device to send an uplink immediately.

* Downlink Payload:

0x08 FF, RS485-BL will immediately send an uplink.

942

943

944

==== Clear RS485 Command ====

945

946

The AT+COMMANDx and AT+DATACUTx settings are stored in special location, user can use below command to clear them.

* AT Command:

**AT+CMDEAR=mm,nn** mm: start position of erase ,nn: stop position of erase

952

953

Etc. AT+CMDEAR=1,10 means erase AT+COMMAND1/AT+DATACUT1 to AT+COMMAND10/AT+DATACUT10

954

955

Example screen shot after clear all RS485 commands.

The uplink screen shot is:

960

961

[[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image023.png]]

* Downlink Payload:

0x09 aa bb same as AT+CMDEAR=aa,bb

967

968

969

==== Set Serial Communication Parameters ====

970

971

Set the Rs485 serial communication parameters:

* AT Command:

Set Baud Rate:

AT+BAUDR=9600 ~/~/ Options: (1200,2400,4800,14400,19200,115200)

Set UART parity

AT+PARITY=0 ~/~/ Option: 0: no parity, 1: odd parity, 2: even parity

Set STOPBIT

AT+STOPBIT=0 ~/~/ Option: 0 for 1bit; 1 for 1.5 bit ; 2 for 2 bits

* Downlink Payload:

A7 01 aa bb: Same AT+BAUDR=hex(aa bb)*100

Example:

* A7 01 00 60 same as AT+BAUDR=9600

997

* A7 01 04 80 same as AT+BAUDR=115200

998

999

A7 02 aa: Same as AT+PARITY=aa (aa value: 00 , 01 or 02)

1000

1001

A7 03 aa: Same as AT+STOPBIT=aa (aa value: 00 , 01 or 02)

1002

1003

1004

==== Control output power duration ====

1005

1006

User can set the output power duration before each sampling.

* AT Command:

Example:

AT+3V3T=1000 ~/~/ 3V3 output power will open 1s before each sampling.

1013

1014

AT+5VT=1000 ~/~/ +5V output power will open 1s before each sampling.

1015

1016

1017

* LoRaWAN Downlink Command:

1018

1019

07 01 aa bb Same as AT+5VT=(aa bb)

1020

1021

07 02 aa bb Same as AT+3V3T=(aa bb)

1.

11. Buttons

|**Button**|**Feature**

1030

|**RST**|Reboot RS485-BL

1.

11. +3V3 Output

RS485-BL has a Controllable +3V3 output, user can use this output to power external sensor.

1036

1037

The +3V3 output will be valid for every sampling. RS485-BL will enable +3V3 output before all sampling and disable the +3V3 after all sampling.

1038

1039

1040

The +3V3 output time can be controlled by AT Command.

**AT+3V3T=1000**

Means set +3v3 valid time to have 1000ms. So, the real +3v3 output will actually have 1000ms + sampling time for other sensors.

1045

1046

1047

By default, the AT+3V3T=0. This is a special case, means the +3V3 output is always on at any time

1.

11. +5V Output

RS485-BL has a Controllable +5V output, user can use this output to power external sensor.

1054

1055

The +5V output will be valid for every sampling. RS485-BL will enable +5V output before all sampling and disable the +5v after all sampling.

1056

1057

1058

The 5V output time can be controlled by AT Command.

**AT+5VT=1000**

Means set 5V valid time to have 1000ms. So, the real 5V output will actually have 1000ms + sampling time for other sensors.

1063

1064

1065

By default, the AT+5VT=0. If the external sensor which require 5v and require more time to get stable state, user can use this command to increase the power ON duration for this sensor.

1.

11. LEDs

|**LEDs**|**Feature**

1074

|**LED1**|Blink when device transmit a packet.

1.

11. Switch Jumper

|**Switch Jumper**|**Feature**

1080

|**SW1**|(((

1081

ISP position: Upgrade firmware via UART

1082

1083

Flash position: Configure device, check running status.

1084

)))

1085

|**SW2**|(((

1086

5V position: set to compatible with 5v I/O.

1087

1088

3.3v position: set to compatible with 3.3v I/O.,

)))

+3.3V: is always ON

+5V: Only open before every sampling. The time is by default, it is AT+5VT=0. Max open time. 5000 ms.

1. Case Study

User can check this URL for some case studies.

1098

1099

[[http:~~/~~/wiki.dragino.com/index.php?title=APP_RS485_COMMUNICATE_WITH_SENSORS>>url:http://wiki.dragino.com/index.php?title=APP_RS485_COMMUNICATE_WITH_SENSORS]]

1. Use AT Command

11. Access AT Command

1106

1107

RS485-BL supports AT Command set. User can use a USB to TTL adapter plus the 3.5mm Program Cable to connect to RS485-BL to use AT command, as below.

1108

1109

[[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image027.png]]

1110

1111

1112

In PC, User needs to set **serial tool**(such as [[putty>>url:https://www.chiark.greenend.org.uk/~~sgtatham/putty/latest.html]], SecureCRT) baud rate to **9600** to access to access serial console of RS485-BL. The default password is 123456. Below is the output for reference:

1113

1114

[[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image028.png]]

More detail AT Command manual can be found at [[AT Command Manual>>path:#AT_COMMAND]]

1.

11. Common AT Command Sequence

1124

111. Multi-channel ABP mode (Use with SX1301/LG308)

1125

1126

If device has not joined network yet:

AT+FDR

AT+NJM=0

ATZ

If device already joined network:

AT+NJM=0

ATZ

1.

11.

111. Single-channel ABP mode (Use with LG01/LG02)

1144

1145

AT+FDR Reset Parameters to Factory Default, Keys Reserve

1146

1147

AT+NJM=0 Set to ABP mode

1148

1149

AT+ADR=0 Set the Adaptive Data Rate Off

1150

1151

AT+DR=5 Set Data Rate

1152

1153

AT+TDC=60000 Set transmit interval to 60 seconds

1154

1155

AT+CHS=868400000 Set transmit frequency to 868.4Mhz

1156

1157

AT+RX2FQ=868400000 Set RX2Frequency to 868.4Mhz (according to the result from server)

1158

1159

AT+RX2DR=5 Set RX2DR to match the downlink DR from server. see below

1160

1161

AT+DADDR=26 01 1A F1 Set Device Address to 26 01 1A F1, this ID can be found in the LoRa Server portal.

ATZ Reset MCU

**Note:**

1. Make sure the device is set to ABP mode in the IoT Server.

1168

1. Make sure the LG01/02 gateway RX frequency is exactly the same as AT+CHS setting.

1169

1. Make sure SF / bandwidth setting in LG01/LG02 match the settings of AT+DR. refer [[this link>>url:http://www.dragino.com/downloads/index.php?dir=LoRa_Gateway/&file=LoRaWAN%201.0.3%20Regional%20Parameters.xlsx]] to see what DR means.

1170

1. The command AT+RX2FQ and AT+RX2DR is to let downlink work. to set the correct parameters, user can check the actually downlink parameters to be used. As below. Which shows the RX2FQ should use 868400000 and RX2DR should be 5

1171

1172

[[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image029.png]]

1. FAQ

11. How to upgrade the image?

1177

1178

The RS485-BL LoRaWAN Controller is shipped with a 3.5mm cable, the cable is used to upload image to RS485-BL to:

1179

1180

* Support new features

1181

* For bug fix

1182

* Change LoRaWAN bands.

1183

1184

Below shows the hardware connection for how to upload an image to RS485-BL:

1185

1186

[[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image030.png]]

1187

1188

**Step1:** Download [[flash loader>>url:https://www.st.com/content/st_com/en/products/development-tools/software-development-tools/stm32-software-development-tools/stm32-programmers/flasher-stm32.html]].

1189

1190

**Step2**: Download the [[LT Image files>>url:http://www.dragino.com/downloads/index.php?dir=LT_LoRa_IO_Controller/LT33222-L/image/]].

1191

1192

**Step3: **Open flashloader; choose the correct COM port to update.

|(((

HOLD PRO then press the RST button, SYS will be ON, then click next

)))

|(((

Board detected

)))

|(((

)))

[[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image031.png]] [[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image032.png]]

[[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image033.png]] [[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image034.png]]

1212

1213

1214

[[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image035.png]] [[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image036.png]]

1.

11. How to change the LoRa Frequency Bands/Region?

1219

1220

User can follow the introduction for [[how to upgrade image>>path:#upgrade_image]]. When download the images, choose the required image file for download.

1.

11. How many RS485-Slave can RS485-BL connects?

1226

1227

The RS485-BL can support max 32 RS485 devices. Each uplink command of RS485-BL can support max 16 different RS485 command. So RS485-BL can support max 16 RS485 devices pre-program in the device for uplink. For other devices no pre-program, user can use the [[downlink message (type code 0xA8) to poll their info>>path:#downlink_A8]].

1. Trouble Shooting

11. Downlink doesn’t work, how to solve it?

1234

1235

Please see this link for debug:

1236

1237

[[http:~~/~~/wiki.dragino.com/index.php?title=Main_Page#LoRaWAN_Communication_Debug>>url:http://wiki.dragino.com/index.php?title=Main_Page#LoRaWAN_Communication_Debug]]

1.

11. Why I can’t join TTN V3 in US915 /AU915 bands?

1243

1244

It might about the channels mapping. Please see for detail.

1245

1246

[[http:~~/~~/wiki.dragino.com/index.php?title=LoRaWAN_Communication_Debug#Notice_of_US915.2FCN470.2FAU915_Frequency_band>>url:http://wiki.dragino.com/index.php?title=LoRaWAN_Communication_Debug#Notice_of_US915.2FCN470.2FAU915_Frequency_band]]

1. Order Info

**Part Number: RS485-BL-XXX**

**XXX:**

* **EU433**: frequency bands EU433

1257

* **EU868**: frequency bands EU868

1258

* **KR920**: frequency bands KR920

1259

* **CN470**: frequency bands CN470

1260

* **AS923**: frequency bands AS923

1261

* **AU915**: frequency bands AU915

1262

* **US915**: frequency bands US915

1263

* **IN865**: frequency bands IN865

1264

* **RU864**: frequency bands RU864

1265

* **KZ865: **frequency bands KZ865

1. Packing Info

**Package Includes**:

1270

1271

* RS485-BL x 1

1272

* Stick Antenna for LoRa RF part x 1

1273

* Program cable x 1

1274

1275

**Dimension and weight**:

1276

1277

* Device Size: 13.5 x 7 x 3 cm

1278

* Device Weight: 105g

1279

* Package Size / pcs : 14.5 x 8 x 5 cm

1280

* Weight / pcs : 170g

1. 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.

1285

* 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

1286

1287

[[support@dragino.com>>url:file:///D:/市场资料/说明书/LoRa/LT系列/support@dragino.com]]

Wiki source code of RS485-BL – Waterproof RS485 to LoRaWAN Converter

Applications

Navigation