RS485-LN – RS485 to LoRaWAN Converter

The Dragino RS485-LN is a (% style="color:blue" %)**RS485 to LoRaWAN Converter**(%%). It converts the RS485 signal into LoRaWAN wireless signal which simplify the IoT installation and reduce the installation/maintaining cost.

28

)))

29

30

(((

31

RS485-LN allows user to (% style="color:blue" %)**monitor / control RS485 devices**(%%) and reach extremely long ranges. It provides ultra-long range spread spectrum communication and high interference immunity whilst minimizing current consumption. It targets professional wireless sensor network applications such as irrigation systems, smart metering, smart cities, smartphone detection, building automation, and so on.

)))

(((

(% style="color:blue" %)**For data uplink**(%%), RS485-LN sends user-defined commands to RS485 devices and gets the return from the RS485 devices. RS485-LN will process these returns according to user-define rules to get the final payload and upload to LoRaWAN server.

)))

(((

(% style="color:blue" %)**For data downlink**(%%), RS485-LN runs in LoRaWAN Class C. When there downlink commands from LoRaWAN server, RS485-LN will forward the commands from LoRaWAN server to RS485 devices.

40

41

(% style="color:blue" %)**Demo Dashboard for RS485-LN**(%%) connect to two energy meters: [[https:~~/~~/app.datacake.de/dashboard/d/58844a26-378d-4c5a-aaf5-b5b5b153447a>>url:https://app.datacake.de/dashboard/d/58844a26-378d-4c5a-aaf5-b5b5b153447a]]

)))

)))

[[image:1653267211009-519.png||height="419" width="724"]]

46

47

48

== 1.2 Specifications ==

**Hardware System:**

* STM32L072CZT6 MCU

* SX1276/78 Wireless Chip

55

* Power Consumption (exclude RS485 device):

56

** Idle: 32mA@12v

57

** 20dB Transmit: 65mA@12v

58

59

**Interface for Model:**

60

61

* RS485

62

* Power Input 7~~ 24V DC.

**LoRa Spec:**

* Frequency Range:

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

68

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

69

* 168 dB maximum link budget.

70

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

71

* +14 dBm high efficiency PA.

72

* Programmable bit rate up to 300 kbps.

73

* High sensitivity: down to -148 dBm.

74

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

75

* Excellent blocking immunity.

76

* Low RX current of 10.3 mA, 200 nA register retention.

77

* Fully integrated synthesizer with a resolution of 61 Hz.

78

* FSK, GFSK, MSK, GMSK, LoRaTM and OOK modulation.

79

* Built-in bit synchronizer for clock recovery.

80

* Preamble detection.

81

* 127 dB Dynamic Range RSSI.

82

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

83

* Packet engine up to 256 bytes with CRC

== 1.3 Features ==

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

89

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

90

* AT Commands to change parameters

91

* Remote configure parameters via LoRa Downlink

92

* Firmware upgradable via program port

93

* Support multiply RS485 devices by flexible rules

94

* Support Modbus protocol

95

* Support Interrupt uplink (Since hardware version v1.2)

96

97

98

== 1.4 Applications ==

99

100

* Smart Buildings & Home Automation

101

* Logistics and Supply Chain Management

* Smart Metering

* Smart Agriculture

* Smart Cities

* Smart Factory

== 1.5 Firmware Change log ==

109

110

[[RS485-LN Image files – Download link and Change log>>url:http://www.dragino.com/downloads/index.php?dir=RS485-LN/]]

111

112

113

== 1.6 Hardware Change log ==

(((

(((

v1.2: Add External Interrupt Pin.

v1.0: Release

)))

)))

= 2. Power ON Device =

126

127

(((

128

The RS485-LN can be powered by 7 ~~ 24V DC power source. Connection as below

129

130

* Power Source VIN to RS485-LN VIN+

131

* Power Source GND to RS485-LN VIN-

132

133

(((

134

Once there is power, the RS485-LN will be on.

135

)))

136

137

[[image:1653268091319-405.png]]

)))

= 3. Operation Mode =

143

144

== 3.1 How it works? ==

145

146

(((

147

The RS485-LN is configured as LoRaWAN OTAA Class C 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-LN. It will auto join the network via OTAA.

)))

== 3.2 Example to join LoRaWAN network ==

153

154

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.

155

156

[[image:1653268155545-638.png||height="334" width="724"]]

(((

(((

The RS485-LN in this example connected to two RS485 devices for demonstration, user can connect to other RS485 devices via the same method. The connection is as below:

)))

(((

485A+ and 485B- of the sensor are connected to RS485A and RA485B of RS485-LN respectively.

166

)))

167

168

[[image:1653268227651-549.png||height="592" width="720"]]

169

170

(((

171

The LG308 is already set to connect to [[TTN V3 network >>path: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-LN.

)))

(((

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

)))

)))

[[image:1652953462722-299.png]]

(((

(((

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]]

196

197

[[image:image-20220519174512-2.png||height="323" width="720"]]

198

199

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

200

201

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

202

203

You can also choose to create the device manually.

204

205

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

206

207

Add APP KEY and DEV EUI

208

209

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

(((

**Step 2**: Power on RS485-LN 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.

214

)))

215

216

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

217

218

219

== 3.3 Configure Commands to read data ==

(((

(((

There are plenty of RS485 devices in the market and each device has different command to read the valid data. To support these devices in flexible, RS485-LN supports flexible command set. User can use [[AT Commands>>||anchor="H3.5ConfigureRS485-BLviaATorDownlink"]] or LoRaWAN Downlink Command to configure what commands RS485-LN should send for each sampling and how to handle the return from RS485 devices.

)))

(((

(% style="color:red" %)Note: below description and commands are for firmware version >v1.1, if you have firmware version v1.0. Please check the [[user manual v1.0>>url:http://www.dragino.com/downloads/index.php?dir=RS485-LN/&file=RS485-LN_UserManual_v1.0.1.pdf]] or upgrade the firmware to v1.1

)))

)))

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

234

235

To use RS485-LN to read data from RS485 sensors, connect the RS485-LN A/B traces to the sensors. And user need to make sure RS485-LN use the match UART setting to access the sensors. The related commands for UART settings are:

236

237

(% border="1" style="background-color:#ffffcc; color:green; width:782px" %)

238

|(% style="width:128px" %)(((

239

**AT Commands**

240

)))|(% style="width:305px" %)(((

241

**Description**

242

)))|(% style="width:346px" %)(((

243

**Example**

244

)))

245

|(% style="width:128px" %)(((

246

AT+BAUDR

247

)))|(% style="width:305px" %)(((

248

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

249

)))|(% style="width:346px" %)(((

(((

AT+BAUDR=9600

)))

(((

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

256

)))

257

)))

258

|(% style="width:128px" %)(((

259

AT+PARITY

260

)))|(% style="width:305px" %)(((

261

Set UART parity (for RS485 connection)

262

)))|(% style="width:346px" %)(((

(((

AT+PARITY=0

)))

(((

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

269

)))

270

)))

271

|(% style="width:128px" %)(((

272

AT+STOPBIT

273

)))|(% style="width:305px" %)(((

274

(((

275

Set serial stopbit (for RS485 connection)

)))

(((

)))

)))|(% style="width:346px" %)(((

282

(((

283

AT+STOPBIT=0 for 1bit

)))

(((

AT+STOPBIT=1 for 1.5 bit

)))

(((

AT+STOPBIT=2 for 2 bits

)))

)))

=== 3.3.2 Configure sensors ===

(((

(((

Some sensors might need to configure before normal operation. User can configure such sensor via PC and RS485 adapter or through RS485-LN AT Commands (% style="color:#4f81bd" %)**AT+CFGDEV**(%%). Each (% style="color:#4f81bd" %)**AT+CFGDEV **(%%)equals to send a RS485 command to sensors. This command will only run when user input it and won’t run during each sampling.

)))

)))

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

304

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

305

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

306

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

307

308

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

309

310

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

311

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

312

313

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

314

315

(((

316

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

317

318

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

319

320

This section describes how to achieve above goals.

321

322

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

323

324

325

**Each RS485 commands include two parts:**

326

327

~1. What commands RS485-LN will send to the RS485 sensors. There are total 15 commands from **AT+COMMAD1**, **ATCOMMAND2**,…, to **AT+COMMANDF**. All commands are of same grammar.

328

329

2. How to get wanted value the from RS485 sensors returns from by 1). There are total 15 AT Commands to handle the return, commands are **AT+DATACUT1**,**AT+DATACUT2**,…, **AT+DATACUTF** corresponding to the commands from 1). All commands are of same grammar.

330

331

3. 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

332

333

334

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

335

336

337

Below are examples for the how above AT Commands works.

338

339

340

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

341

342

(% border="1" style="background-color:#4bacc6; color:white; width:499px" %)

343

|(% style="width:496px" %)(((

344

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

345

346

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

347

348

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

349

)))

350

351

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.

352

353

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

354

355

356

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

357

358

(% border="1" style="background-color:#4bacc6; color:white; width:725px" %)

359

|(% style="width:722px" %)(((

360

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

361

362

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

363

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

364

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

)))

**Examples:**

* Grab bytes:

[[image:image-20220602153621-1.png]]

* Grab a section.

[[image:image-20220602153621-2.png]]

377

378

379

* Grab different sections.

380

381

[[image:image-20220602153621-3.png]]

)))

=== 3.3.4 Compose the uplink payload ===

387

388

(((

389

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:#037691" %)**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.

414

)))

415

416

[[image:1653269759169-150.png||height="513" width="716"]]

417

418

419

(% style="color:#037691" %)**Examples: AT+DATAUP=1**

420

421

422

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**

427

428

1. PAYVER: Defined by AT+PAYVER

429

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

430

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

431

1. DATA: Valid value: max 8 bytes for each uplink so each uplink <= 11 bytes. For the last uplink, DATA will might less than 8 bytes

432

433

[[image:image-20220602155039-4.png]]

434

435

436

So totally there will be 3 uplinks for this sampling, each uplink include 8 bytes DATA

437

438

DATA1=RETURN1 Valid Value + the first two of Valid value of RETURN10= **20 20 0a 33 90 41 02 aa**

439

440

DATA2=3^^rd^^ ~~ 10^^th^^ byte of Valid value of RETURN10= **05 81 0a 20 20 20 20 2d**

441

442

DATA3=the rest of Valid value of RETURN10= **30**

443

444

445

(% style="color:red" %)Notice: In firmware v1.3, the Max bytes has been changed according to the max bytes in different Frequency Bands for lowest SF. As below:

446

447

~* For AU915/AS923 bands, if UplinkDwell time=0, max 51 bytes for each uplink.

448

449

* For AU915/AS923 bands, if UplinkDwell time=0, max 11 bytes for each uplink.

450

451

* For US915 band, max 11 bytes for each uplink.

452

453

~* For all other bands: max 51 bytes for each uplink.

454

455

456

Below are the uplink payloads:

457

458

[[image:1654157178836-407.png]]

459

460

461

=== 3.3.5 Uplink on demand ===

462

463

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

464

465

Downlink control command:

466

467

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

468

469

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

=== 3.3.6 Uplink on Interrupt ===

474

475

RS485-LN support external Interrupt uplink since hardware v1.2 release.

476

477

[[image:1654157342174-798.png]]

478

479

Connect the Interrupt pin to RS485-LN INT port and connect the GND pin to V- port. When there is a high voltage (Max 24v) on INT pin. Device will send an uplink packet.

480

481

482

== 3.4 Uplink Payload ==

483

484

(% border="1" style="background-color:#4bacc6; color:white; width:734px" %)

485

|**Size(bytes)**|(% style="width:120px" %)**2**|(% style="width:116px" %)**1**|(% style="width:386px" %)**Length depends on the return from the commands**

486

|Value|(% style="width:120px" %)(((

Battery(mV)

&

Interrupt _Flag

)))|(% style="width:116px" %)(((

PAYLOAD_VER

)))|(% style="width:386px" %)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.

497

498

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

499

500

501

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

502

503

User can configure RS485-LN via AT Commands or LoRaWAN Downlink Commands

504

505

There are two kinds of Commands:

506

507

* (% style="color:#4f81bd" %)**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: [[End Device AT Commands and Downlink Command>>doc:Main.End Device AT Commands and Downlink Command.WebHome]]

508

509

* (% style="color:#4f81bd" %)**Sensor Related Commands**(%%): These commands are special designed for RS485-LN. User can see these commands below:

510

511

=== 3.5.1 Common Commands ===

512

513

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: [[End Device AT Commands and Downlink Command>>doc:Main.End Device AT Commands and Downlink Command.WebHome]]

514

515

516

=== 3.5.2 Sensor related commands ===

517

518

Response feature is added to the server's downlink, a special package with a FPort of 200 will be uploaded immediately after receiving the data sent by the server.

519

520

[[image:image-20220602163333-5.png||height="263" width="1160"]]

521

522

The first byte of this package represents whether the configuration is successful, 00 represents failure, 01 represents success. Except for the first byte, the other is the previous downlink. (All commands except A8 type commands are applicable)

523

524

525

=== 3.5.3 Sensor related commands ===

==== **RS485 Debug Command** ====

530

531

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

* **AT Command**

(% class="box infomessage" %)

536

(((

537

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

538

)))

539

540

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

541

542

* **Downlink Payload**

543

544

Format: A8 MM NN XX XX XX XX YY

Where:

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

549

* NN: The length of RS485 command

550

* XX XX XX XX: RS485 command total NN bytes

551

* YY: How many bytes will be uplink from the return of this RS485 command,

552

** if YY=0, RS485-LN will execute the downlink command without uplink;

553

** if YY>0, RS485-LN will uplink total YY bytes from the output of this RS485 command; Fport=200

554

** if YY=FF, RS485-LN will uplink RS485 output with the downlink command content; Fport=200.

555

556

**Example 1** ~-~-> Configure without ask for uplink (YY=0)

557

558

To connect a Modbus Alarm with below commands.

559

560

* 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.

561

562

* 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.

563

564

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

565

566

(% style="color:#4f81bd" %)**A8 01 06 0A 05 00 04 00 01 00**(%%): to activate the RS485 Alarm

567

568

(% style="color:#4f81bd" %)**A8 01 06 0A 05 00 04 00 00 00**(%%): to deactivate the RS485 Alarm

569

570

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.

571

572

573

**Example 2** ~-~-> Configure with requesting uplink and original downlink command (**YY=FF**)

574

575

User in IoT server send a downlink command: (% style="color:#4f81bd" %)**A8 01 06 0A 08 00 04 00 01 YY**

576

577

578

RS485-LN got this downlink command and send (% style="color:#4f81bd" %)**0A 08 00 04 00 01 **(%%)to Modbus network. One of the RS485 sensor in the network send back Modbus reply **0A 08 00 04 00 00**. RS485-LN get this reply and combine with the original downlink command and uplink. The uplink message is:

579

580

**A8** (% style="color:#4f81bd" %)**0A 08 00 04 00 **(% style="color:red" %)**01 06** ** **(% style="color:green" %)**0A 08 00 04 00 00**

581

582

[[image:1654159460680-153.png]]

==== **Set Payload version** ====

587

588

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:**

(% class="box infomessage" %)

593

(((

594

**AT+PAYVER: Set PAYVER field = 1**

595

)))

596

597

* **Downlink Payload:**

598

599

**0xAE 01** ~-~-> Set PAYVER field = 0x01

600

601

**0xAE 0F** ~-~-> Set PAYVER field = 0x0F

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

606

607

AT+COMMANDx or AT+DATACUTx

608

609

These three commands are used to configure how the RS485-LN polling data from Modbus device. Detail of usage please see : [[polling RS485 device>>||anchor="H3.3.3Configurereadcommandsforeachsampling"]].

* **AT Command:**

(% class="box infomessage" %)

615

(((

616

**AT+COMMANDx: Configure RS485 read command to sensor.**

617

)))

618

619

(% class="box infomessage" %)

620

(((

621

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

)))

* **Downlink Payload:**

626

627

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

628

629

(% style="color:red" %)**Note**(%%): if user use AT+COMMANDx to add a new command, he also need to send AT+DATACUTx downlink.

630

631

Format: AF MM NN LL XX XX XX XX YY

Where:

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

636

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

637

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

638

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

639

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

**Example:**

(% style="color:#037691" %)**AF 03 01 06 0A 05 00 04 00 01 00**(%%): Same as AT+COMMAND3=0A 05 00 04 00 01,1

644

645

(% style="color:#037691" %)**AF 03 02 06**(% style="color:orange" %)** 10 **(% style="color:red" %)**01 **(% style="color:green" %)**05 06 09 0A**(% style="color:#037691" %)** 00**(%%): Same as AT+DATACUT3=(% style="color:orange" %)**16**(%%),(% style="color:red" %)**1**(%%),(% style="color:green" %)**5+6+9+10**

646

647

(% style="color:#037691" %)**AF 03 02 06 **(% style="color:orange" %)**0B**(% style="color:red" %)** 02 **(% style="color:green" %)**05 07 08 0A **(% style="color:#037691" %)**00**(%%): Same as AT+DATACUT3=(% style="color:orange" %)**11**(%%),(% style="color:red" %)**2**(%%),(% style="color:green" %)**5~~7+8~~10**

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

652

653

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]].

654

655

This command is valid since v1.3 firmware version

656

657

AT+MBFUN 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.

**Example:**

* AT+MBFUN=1 and AT+DATACUT1/AT+DATACUT2 are not configure (0,0,0). So RS485-LN.

663

* 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.

664

* 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.

665

666

[[image:image-20220602165351-6.png]]

667

668

[[image:image-20220602165351-7.png]]

==== **RS485 command timeout** ====

673

674

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

675

676

Default value: 0, range: 0 ~~ 65 seconds

* **AT Command:**

(% class="box infomessage" %)

681

(((

682

**AT+CMDDLaa=hex(bb cc)*1000**

)))

**Example:**

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

688

689

690

* **Downlink Payload:**

**0x AA aa bb cc**

Same as: AT+CMDDLaa=hex(bb cc)*1000

**Example:**

0xAA 01 00 01 ~-~-> Same as **AT+CMDDL1=1000 ms**

==== **Uplink payload mode** ====

703

704

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

705

706

The use of this command please see: [[Compose Uplink payload>>||anchor="H3.3.4Composetheuplinkpayload"]]

* **AT Command:**

(% class="box infomessage" %)

(((

**AT+DATAUP=0**

)))

(% class="box infomessage" %)

(((

**AT+DATAUP=1**

)))

* **Downlink Payload:**

722

723

**0xAD 00** **~-~->** Same as AT+DATAUP=0

724

725

**0xAD 01** **~-~->** Same as AT+DATAUP=1

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

730

731

Ask device to send an uplink immediately.

* **AT Command:**

No AT Command for this, user can press the [[ACT button>>path:#Button]] for 1 second for the same.

736

737

738

* **Downlink Payload:**

739

740

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

==== **Clear RS485 Command** ====

745

746

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

751

752

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

753

754

Example screen shot after clear all RS485 commands.

755

756

757

The uplink screen shot is:

758

759

[[image:1654160691922-496.png]][[image:file:///C:/Users/93456/AppData/Local/Temp/msohtmlclip1/01/clip_image001.png]]

760

761

762

* **Downlink Payload:**

763

764

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

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

769

770

Set the Rs485 serial communication parameters:

* **AT Command:**

Set Baud Rate:

(% class="box infomessage" %)

777

(((

778

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

)))

Set UART Parity

(% class="box infomessage" %)

784

(((

785

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

)))

Set STOPBIT

(% class="box infomessage" %)

791

(((

792

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

)))

* **Downlink Payload:**

797

798

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

**Example:**

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

803

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

804

805

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

806

807

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

808

809

810

== 3.6 Listening mode for RS485 network ==

811

812

This feature support since firmware v1.4

813

814

RS485-LN supports listening mode, it can listen the RS485 network packets and send them via LoRaWAN uplink. Below is the structure. The blue arrow shows the RS485 network packets to RS485-LN.

815

816

[[image:image-20220602171200-8.png||height="567" width="1007"]]

817

818

To enable the listening mode, use can run the command AT+RXMODE.

819

820

821

(% border="1" style="background-color:#ffffcc; width:500px" %)

822

|=(% style="width: 161px;" %)**Command example:**|=(% style="width: 337px;" %)**Function**

823

|(% style="width:161px" %)AT+RXMODE=1,10 |(% style="width:337px" %)Enable listening mode 1, if RS485-LN has received more than 10 RS485 commands from the network. RS485-LN will send these commands via LoRaWAN uplinks.

824

|(% style="width:161px" %)AT+RXMODE=2,500|(% style="width:337px" %)Enable listening mode 2, RS485-LN will capture and send a 500ms content once from the first detect of character. Max value is 65535 ms

825

|(% style="width:161px" %)AT+RXMODE=0,0|(% style="width:337px" %)Disable listening mode. This is the default settings.

826

|(% style="width:161px" %) |(% style="width:337px" %)A6 aa bb cc same as AT+RXMODE=aa,(bb<<8 ~| cc)

827

828

**Downlink Command:**

829

830

**0xA6 aa bb cc ** same as AT+RXMODE=aa,(bb<<8 | cc)

**Example**:

The RS485-LN is set to AT+RXMODE=2,1000

836

837

There is a two Modbus commands in the RS485 network as below:

838

839

The Modbus master send a command: (% style="background-color:#ffc000" %)01 03 00 00 00 02 c4 0b

840

841

And Modbus slave reply with: (% style="background-color:green" %)01 03 04 00 00 00 00 fa 33

842

843

RS485-LN will capture both and send the uplink: (% style="background-color:#ffc000" %)01 03 00 00 00 02 c4 0b (% style="background-color:green" %)01 03 04 00 00 00 00 fa 33

844

845

[[image:image-20220602171200-9.png]]

846

847

848

(% style="color:red" %)Notice: Listening mode can work with the default polling mode of RS485-LN. When RS485-LN is in to send the RS485 commands (from AT+COMMANDx), the listening mode will be interrupt for a while.

== 3.7 Buttons ==

(% border="1" style="background-color:#f7faff; width:500px" %)

855

|=**Button**|=(% style="width: 1420px;" %)**Feature**

856

|**ACT**|(% style="width:1420px" %)If RS485 joined in network, press this button for more than 1 second, RS485 will upload a packet, and the SYS LED will give a (% style="color:blue" %)**Blue blink**

857

|**RST**|(% style="width:1420px" %)Reboot RS485

858

|**PRO**|(% style="width:1420px" %)Use for upload image, see [[How to Update Image>>path:#upgrade_image]]

== 3.8 LEDs ==

(% border="1" style="background-color:#f7faff; width:500px" %)

864

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

865

|**PWR**|Always on if there is power

866

|**SYS**|After device is powered on, the SYS will (% style="color:green" %)**fast blink in GREEN** (%%)for 5 times, means RS485-LN start to join LoRaWAN network. If join success, SYS will be (% style="color:green" %)**on GREEN for 5 seconds**(%%)**. **SYS will (% style="color:green" %)**blink Blue**(%%) on every upload and (% style="color:green" %)**blink Green**(%%) once receive a downlink message.

= 4. Case Study =

User can check this URL for some case studies: [[APP RS485 COMMUNICATE WITH SENSORS>>doc:Main.Application Note \: Communicate with Different Sensors ----- RS485-LN RS485-BL.WebHome]]

872

873

874

= 5. Use AT Command =

875

876

== 5.1 Access AT Command ==

877

878

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.

879

880

[[image:1654162355560-817.png]]

881

882

883

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

884

885

[[image:1654162368066-342.png]]

886

887

888

More detail AT Command manual can be found at [[AT Command Manual>>||anchor="3.5ConfigureRS485-BLviaATorDownlink"]]

889

890

891

== 5.2 Common AT Command Sequence ==

892

893

=== 5.2.1 Multi-channel ABP mode (Use with SX1301/LG308) ===

894

895

If device has not joined network yet:

896

897

(% class="box infomessage" %)

(((

**AT+FDR**

)))

(% class="box infomessage" %)

(((

**AT+NJM=0**

)))

(% class="box infomessage" %)

(((

**ATZ**

)))

If device already joined network:

914

915

(% class="box infomessage" %)

(((

**AT+NJM=0**

)))

(% class="box infomessage" %)

(((

**ATZ**

)))

=== 5.5.2 Single-channel ABP mode (Use with LG01/LG02) ===

927

928

929

(% style="background-color:#dcdcdc" %)**AT+FDR** (%%) Reset Parameters to Factory Default, Keys Reserve

930

931

(% style="background-color:#dcdcdc" %)**AT+NJM=0 **(%%)Set to ABP mode

932

933

(% style="background-color:#dcdcdc" %)**AT+ADR=0** (%%)Set the Adaptive Data Rate Off

934

935

(% style="background-color:#dcdcdc" %)**AT+DR=5** (%%)Set Data Rate

936

937

(% style="background-color:#dcdcdc" %)**AT+TDC=60000** (%%) Set transmit interval to 60 seconds

938

939

(% style="background-color:#dcdcdc" %)**AT+CHS=868400000**(%%) Set transmit frequency to 868.4Mhz

940

941

(% style="background-color:#dcdcdc" %)**AT+RX2FQ=868400000** (%%) Set RX2Frequency to 868.4Mhz (according to the result from server)

942

943

(% style="background-color:#dcdcdc" %)**AT+RX2DR=5** (%%) Set RX2DR to match the downlink DR from server. see below

944

945

(% style="background-color:#dcdcdc" %)**AT+DADDR=26** (%%) 01 1A F1 Set Device Address to 26 01 1A F1, this ID can be found in the LoRa Server portal.

946

947

(% style="background-color:#dcdcdc" %)**ATZ** (%%) Reset MCU

948

949

950

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

951

952

(% style="color:red" %)1. Make sure the device is set to ABP mode in the IoT Server.

953

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

954

3. 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.

955

4. 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

956

957

[[image:1654162478620-421.png]]

= 6. FAQ =

== 6.1 How to upgrade the image? ==

963

964

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

965

966

* Support new features

967

* For bug fix

968

* Change LoRaWAN bands.

969

970

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

971

972

[[image:1654162535040-878.png]]

973

974

**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]].

975

976

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

977

978

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

979

980

(% style="color:blue" %) Hold down the PRO button and then momentarily press the RST reset button and the SYS led will change from OFF to ON, While SYS LED is RED ON, it means the RS485-LN is ready to be program.

981

982

983

[[image:image-20220602175818-12.png]]

984

985

986

[[image:image-20220602175848-13.png]]

987

988

989

[[image:image-20220602175912-14.png]]

990

991

992

**Notice**: In case user has lost the program cable. User can hand made one from a 3.5mm cable. The pin mapping is:

993

994

[[image:image-20220602175638-10.png]]

995

996

997

== 6.2 How to change the LoRa Frequency Bands/Region? ==

998

999

User can follow the introduction for [[how to upgrade image>>||anchor="H6.1Howtoupgradetheimage3F"]]. When download the images, choose the required image file for download.

1000

1001

1002

== 6.3 How many RS485-Slave can RS485-BL connects? ==

1003

1004

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>>||anchor="H3.3.3Configurereadcommandsforeachsampling"]].

1005

1006

1007

== 6.4 Compatible question to ChirpStack and TTI LoRaWAN server ? ==

1008

1009

When user need to use with ChirpStack or TTI. Please set AT+RPL=4.

1010

1011

Detail info check this link: [[Set Packet Receiving Response Level>>doc:Main.End Device AT Commands and Downlink Command.WebHome||anchor="H7.23SetPacketReceivingResponseLevel"]]

1012

1013

1014

= 7. Trouble Shooting =

1015

1016

== 7.1 Downlink doesn’t work, how to solve it? ==

1017

1018

Please see this link for debug: [[LoRaWAN Communication Debug>>doc:Main.LoRaWAN Communication Debug.WebHome]]

1019

1020

1021

== 7.2 Why I can’t join TTN V3 in US915 /AU915 bands? ==

1022

1023

It might about the channels mapping. Please see for detail: [[Notice of Frequency band>>doc:Main.LoRaWAN Communication Debug.WebHome||anchor="H2.NoticeofUS9152FCN4702FAU915Frequencyband"]]

= 8. Order Info =

(% style="color:blue" %)**Part Number: RS485-LN-XXX**

1029

1030

(% style="color:blue" %)**XXX:**

1031

1032

* (% style="color:blue" %)**EU433**(%%): frequency bands EU433

1033

* (% style="color:blue" %)**EU868**(%%): frequency bands EU868

1034

* (% style="color:blue" %)**KR920**(%%): frequency bands KR920

1035

* (% style="color:blue" %)**CN470**(%%): frequency bands CN470

1036

* (% style="color:blue" %)**AS923**(%%): frequency bands AS923

1037

* (% style="color:blue" %)**AU915**(%%): frequency bands AU915

1038

* (% style="color:blue" %)**US915**(%%): frequency bands US915

1039

* (% style="color:blue" %)**IN865**(%%): frequency bands IN865

1040

* (% style="color:blue" %)**RU864**(%%): frequency bands RU864

1041

* (% style="color:blue" %)**KZ865**(%%): frequency bands KZ865

= 9.Packing Info =

**Package Includes**:

1048

1049

* RS485-LN x 1

1050

* Stick Antenna for LoRa RF part x 1

1051

* Program cable x 1

1052

1053

**Dimension and weight**:

1054

1055

* Device Size: 13.5 x 7 x 3 cm

1056

* Device Weight: 105g

1057

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

1058

* Weight / pcs : 170g

1059

1060

1061

= 10. FCC Caution for RS485LN-US915 =

1062

1063

Any Changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment.

1064

1065

This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.

**IMPORTANT NOTE:**

**Note: **This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:

1071

1072

—Reorient or relocate the receiving antenna.

1073

1074

—Increase the separation between the equipment and receiver.

1075

1076

—Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.

1077

1078

—Consult the dealer or an experienced radio/TV technician for help.

1079

1080

1081

**FCC Radiation Exposure Statement:**

1082

1083

This equipment complies with FCC radiation exposure limits set forth for an uncontrolled environment.This equipment should be installed and operated with minimum distance 20cm between the radiator& your body.

= 11. 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.

1089

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

Wiki source code of RS485-LN – RS485 to LoRaWAN Converter

Applications

Navigation