Changes for page RS485-LN – RS485 to LoRaWAN Converter User Manual
Last modified by Karry Zhuang on 2025/03/06 16:34
Summary
-
Page properties (1 modified, 0 added, 0 removed)
-
Attachments (0 modified, 0 added, 3 removed)
Details
- Page properties
-
- Content
-
... ... @@ -290,7 +290,6 @@ 290 290 ))) 291 291 292 292 293 - 294 294 === 3.3.2 Configure sensors === 295 295 296 296 ((( ... ... @@ -314,34 +314,77 @@ 314 314 === 3.3.3 Configure read commands for each sampling === 315 315 316 316 ((( 317 -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. 316 +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. 317 +))) 318 318 319 +((( 320 +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. 321 +))) 322 + 323 +((( 319 319 To save the LoRaWAN network bandwidth, we might need to read data from different sensors and combine their valid value into a short payload. 325 +))) 320 320 327 +((( 321 321 This section describes how to achieve above goals. 329 +))) 322 322 323 -During each sampling, the RS485-LN can support 15 commands to read sensors. And combine the return to one or several uplink payloads. 331 +((( 332 +During each sampling, the RS485-BL can support 15 commands to read sensors. And combine the return to one or several uplink payloads. 333 +))) 324 324 335 +((( 336 +**Command from RS485-BL to Sensor:** 337 +))) 325 325 326 -**Each RS485 commands include two parts:** 339 +((( 340 +RS485-BL can send out pre-set max 15 strings via **AT+COMMAD1**, **ATCOMMAND2**,…, to **AT+COMMANDF** . All commands are of same grammar. 341 +))) 327 327 328 -~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. 343 +((( 344 +**Handle return from sensors to RS485-BL**: 345 +))) 329 329 330 -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. 347 +((( 348 +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** 349 +))) 331 331 332 -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 351 +* ((( 352 +**AT+DATACUT** 353 +))) 333 333 355 +((( 356 +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. 357 +))) 334 334 359 +* ((( 360 +**AT+SEARCH** 361 +))) 362 + 363 +((( 364 +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. 365 +))) 366 + 367 +((( 368 +**Define wait timeout:** 369 +))) 370 + 371 +((( 372 +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 373 +))) 374 + 375 +((( 335 335 After we got the valid value from each RS485 commands, we need to combine them together with the command **AT+DATAUP**. 377 +))) 336 336 379 +**Examples:** 337 337 338 338 Below are examples for the how above AT Commands works. 339 339 383 +**AT+COMMANDx : **This command will be sent to RS485/TTL devices during each sampling, Max command length is 14 bytes. The grammar is: 340 340 341 -**AT+COMMANDx : **This command will be sent to RS485 devices during each sampling, Max command length is 14 bytes. The grammar is: 342 - 343 -(% border="1" style="background-color:#4bacc6; color:white; width:499px" %) 344 -|(% style="width:496px" %)((( 385 +(% border="1" class="table-bordered" %) 386 +|((( 345 345 **AT+COMMANDx=xx xx xx xx xx xx xx xx xx xx xx xx,m** 346 346 347 347 **xx xx xx xx xx xx xx xx xx xx xx xx: The RS485 command to be sent** ... ... @@ -349,42 +349,90 @@ 349 349 **m: 0: no CRC, 1: add CRC-16/MODBUS in the end of this command** 350 350 ))) 351 351 394 +((( 352 352 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. 396 +))) 353 353 354 -In the RS485-LN, we should use this command AT+COMMAND1=01 03 0B B8 00 02,1 for the same. 398 +((( 399 +In the RS485-BL, we should use this command AT+COMMAND1=01 03 0B B8 00 02,1 for the same. 400 +))) 355 355 402 +((( 403 +**AT+SEARCHx**: This command defines how to handle the return from AT+COMMANDx. 404 +))) 356 356 406 +(% border="1" class="table-bordered" %) 407 +|((( 408 +**AT+SEARCHx=aa,xx xx xx xx xx** 409 + 410 +* **aa: 1: prefix match mode; 2: prefix and suffix match mode** 411 +* **xx xx xx xx xx: match string. Max 5 bytes for prefix and 5 bytes for suffix** 412 + 413 + 414 +))) 415 + 416 +**Examples:** 417 + 418 +~1. For a return string from AT+COMMAND1: 16 0c 1e 56 34 2e 30 58 5f 36 41 30 31 00 49 419 + 420 +If we set AT+SEARCH1=1,1E 56 34. (max 5 bytes for prefix) 421 + 422 +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** 423 + 424 +[[image:1653269403619-508.png]] 425 + 426 +2. For a return string from AT+COMMAND1: 16 0c 1e 56 34 2e 30 58 5f 36 41 30 31 00 49 427 + 428 +If we set AT+SEARCH1=2, 1E 56 34+31 00 49 429 + 430 +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** 431 + 432 +[[image:1653269438444-278.png]] 433 + 357 357 **AT+DATACUTx : **This command defines how to handle the return from AT+COMMANDx, max return length is 45 bytes. 358 358 359 -(% border="1" style="background-color:#4bacc6; color:white; width:725px" %) 360 -|(% style="width:722px" %)((( 436 +|((( 361 361 **AT+DATACUTx=a,b,c** 362 362 363 363 * **a: length for the return of AT+COMMAND** 364 364 * **b:1: grab valid value by byte, max 6 bytes. 2: grab valid value by bytes section, max 3 sections.** 365 -* **c: define the position for valid value. 441 +* **c: define the position for valid value. ** 366 366 ))) 367 367 444 +Examples: 368 368 369 -**Examples:** 370 - 371 371 * Grab bytes: 372 372 373 -[[image: image-20220602153621-1.png]]448 +[[image:1653269551753-223.png||height="311" width="717"]] 374 374 375 - 376 376 * Grab a section. 377 377 378 -[[image: image-20220602153621-2.png]]452 +[[image:1653269568276-930.png||height="325" width="718"]] 379 379 380 - 381 381 * Grab different sections. 382 382 383 -[[image: image-20220602153621-3.png]]456 +[[image:1653269593172-426.png||height="303" width="725"]] 384 384 385 - 386 -))) 458 +(% style="color:red" %)**Note:** 387 387 460 +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. 461 + 462 +Example: 463 + 464 +(% style="color:red" %)AT+COMMAND1=11 01 1E D0,0 465 + 466 +(% style="color:red" %)AT+SEARCH1=1,1E 56 34 467 + 468 +(% style="color:red" %)AT+DATACUT1=0,2,1~~5 469 + 470 +(% style="color:red" %)Return string from AT+COMMAND1: 16 0c 1e 56 34 2e 30 58 5f 36 41 30 31 00 49 471 + 472 +(% style="color:red" %)String after SEARCH command: 2e 30 58 5f 36 41 30 31 00 49 473 + 474 +(% style="color:red" %)Valid payload after DataCUT command: 2e 30 58 5f 36 475 + 476 +[[image:1653269618463-608.png]] 477 + 388 388 === 3.3.4 Compose the uplink payload === 389 389 390 390 (((
- image-20220602153621-1.png
-
- Author
-
... ... @@ -1,1 +1,0 @@ 1 -XWiki.Xiaoling - Size
-
... ... @@ -1,1 +1,0 @@ 1 -23.4 KB - Content
- image-20220602153621-2.png
-
- Author
-
... ... @@ -1,1 +1,0 @@ 1 -XWiki.Xiaoling - Size
-
... ... @@ -1,1 +1,0 @@ 1 -22.2 KB - Content
- image-20220602153621-3.png
-
- Author
-
... ... @@ -1,1 +1,0 @@ 1 -XWiki.Xiaoling - Size
-
... ... @@ -1,1 +1,0 @@ 1 -22.3 KB - Content