Wiki source code of LoRaWAN Communication Debug

Version 101.1 by Bei Jinggeng on 2025/04/29 13:57

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1 **~ Table of Contents:**
2
3 {{toc/}}
4
5
6
7 = 1. Join process page check =
8
9
10 These pages are useful to check what is wrong on the Join process. Below shows the four steps that we can check the Join Process.
11 \\**If user has checked below steps and still can't solve the problem, please send us (support @ dragino.com) the sceenshots for each step to check. They include:**
12
13 * End node console to show the Join freuqency and DR. (If possible)
14
15 * Gateway (from gateway UI) traffic to show the packet got from end node and receive from Server. (If possible)
16
17 * Gateway traffic (from server UI) to shows the data exchange between gateway and server. (Normaly possible)
18
19 * End Node traffic (from server UI) to shows end node activity in server. (Normaly possible)
20
21 * End Node Keys screen shot shows in end node and server. so we can check if the keys are correct. (In most case, we found keys doesn't match, especially APP EUI)
22
23 (% style="color:blue" %)**1. End Device Join Screen shot, we can check:**
24
25 * If the device is sending join request to server?
26
27 * What frequency the device is sending?
28
29 [[image:image-20240129142147-2.png||height="736" width="964"]]
30
31 Console Output from End device to see the transmit frequency.
32
33
34 (% style="color:blue" %)**2. Gateway packet traffic in gateway web or ssh. we can check:**
35
36 * If the gateway receive the Join request packet from sensor? (If this fail, check if the gateway and sensor works on the match frequency)
37
38 * If the gateway gets the Join Accept message from server and transmit it via LoRa?
39
40 [[image:image-20240129151608-6.jpeg||height="725" width="1256"]]
41
42 Console Output from Gateway to see packets between end node and server.
43
44
45 (% style="color:blue" %)**3. Gateway Live data in LoRaWAN Server**
46
47 * Does the gateway real-time data contain information about Join Request? If not, check the internet connection and gateway LoRaWAN server Settings.
48
49 * Does the server send back a Join Accept for the Join Request? If not, check that the key from the device matches the key you put into the server, or try to choose a different server route for that end device.
50
51 * If the Join Accept message are in correct frequency? If you set the server to use US915 band, and your end node and gateway is EU868, you will see the Join Accept message are in US915 band so no possible to Join success.
52
53 [[image:image-20240129150821-5.jpeg||height="522" width="1264"]]
54
55 The Traffic for the End node in the server, use TTN as example.
56
57
58 (% style="color:blue" %)**4. Data Page in LoRaWAN server**
59
60 * If this data page shows the Join Request message from the end node? If not, most properly you have wrong settings in the keys. Keys in the server doesn't match the keys in End Node.
61
62 [[image:image-20240129142557-3.png||height="488" width="1267"]]
63
64 The data for the end device set in server
65
66
67 [[image:image-20240129142631-4.png||height="637" width="1256"]]
68
69 Check if OTAA Keys match the keys in device.
70
71
72 = 2. Notice of US915/CN470/AU915 Frequency band =
73
74
75 (((
76 If user has problem to work with LoRaWAN server in band US915/AU915/CN470, he can check:
77 )))
78
79 * (((
80 What **sub-band** the server support?
81 )))
82 * (((
83 What is the **sub-band** the gateway support?
84 )))
85 * (((
86 What is the **sub-band** the end node is using?
87 )))
88
89 (((
90 All of above should match so End Node can properly Join the server and don't have packet lost.
91 )))
92
93 (((
94
95 )))
96
97 (((
98 In LoRaWAN protocol, the frequency bands US915, AU915, CN470 each includes at least 72 frequencies. Many gateways support only 8 or 16 frequencies, and server might support 8 frequency only. In this case, the OTAA join time and uplink schedule is long and unpredictable while the end node is hopping in 72 frequencies, because the end node will send data in many frequency that the gateway or server doesn't support.
99 )))
100
101 (((
102
103 )))
104
105 (((
106 Here are the frequency tables for these bands as reference:
107 )))
108
109 [[image:image-20220526163801-6.png]]
110
111 US915 Channels
112
113
114 [[image:image-20220526163926-7.png]]
115
116 AU915 Channels
117
118
119 [[image:image-20220526163941-8.png]]
120
121 (((
122 CN470 Channels
123
124
125 )))
126
127 (((
128 If we look at the [[TTN network server frequency plan>>url:https://www.thethingsnetwork.org/docs/lorawan/frequency-plans.html]], we can see the US915 frequency band use the channel 8~~15.So the End Node must work at the same frequency in US915 8~~15 channels for TTN server.
129 )))
130
131 [[image:image-20240123151225-3.png||height="434" width="902"]]
132
133 (((
134 TTN FREQUENCY PLAN
135
136 (% style="display:none" %) (%%)
137 )))
138
139 (((
140 In dragino end node, user can use AT+CHE command to set what frequencies set the end node will use. The default settings for Dragino end node are preconfigure for TTN server, so use 8~~15 channels, which is **AT+CHE=2**. (AT+CHE=1 for first 8 channels, AT+CHE=2 for second 8 channels.. etc, and AT+CHE=0 for all 72 channels. )
141 )))
142
143 (% style="display:none" %) (%%)
144
145 = 3. Why I see data lost/ is not periodically uplink? Even the signal strength is good =
146
147
148 In this case, we can check if the frequency band matches in End Node, Gateway and LoRaWAN server. A typical case is using US915 in ChirpStack server as below:
149
150 * (% style="color:blue" %)**End node** (%%) ~-~-> Use Sub-band2 (Channel 8,9,10,11,12,13,14,15) for Dragino Sensor. ADR is also enable, this is the default settings for dragino sensors.
151
152 * (% style="color:blue" %)**Gateway** (%%) ~-~-> Use Sub-band2 (Channel 8,9,10,11,12,13,14,15) for Dragino Gateway. this is the default settings for dragino sensors.
153
154 * (% style="color:blue" %)**LoRaWAN server**  (%%) ~-~-> ChirpStack default installation and use Sub-band1, **enabled_uplink_channels=[0, 1, 2, 3, 4, 5, 6, 7]** in the file chirpstack-network-server.toml.
155
156 (((
157 When Sensor power on, it will use sub-band2 to join the network, the frequency matches the settings in gateway so all Join Request will be passed to the server for Join. Server will ask the sensor to change to Sub-band1 in the Join Accept downlink message. Sensor will change to sub-band1 for data upload. This cause the sensor and gateway have different frequencies so user see lost of most data or even no data.
158 )))
159
160
161 (((
162 Use Subband2 as a default subband cause the sensor to have problem to work with the LoRaWAN server which use other subband, and use need to access to the end node to change the subband by console. that is not user frendily,. So since Dragino LoRaWAN Stack version DLS-005(release on end of 2020), we have changed the device to use All Subbands for OTAA join, for example, device will use the first frequency in Sub-Band1 as firt OTAA join packet, then use the first frequency in Sub-Band 2 , then first frequency in sub-band 3, and so on. LoRaWAN server will normally provide the required subband in the OTAA accept process, so end node will know what subband it use after join. If LoRaWAN server doesn't provide subband info in OTAA join, end node will use the subband which join success as the working subband. So the new method cause a longer OTAA Join time but will be compatible with all LoRaWAN server. And new method won't affect the normal uplink after Join Success.
163 )))
164
165
166 = 4. Why i see packet lost =
167
168 == **1. Signal problem** ==
169
170
171 1)  (% style="color:blue" %)**ADR automatic adjustment** (%%)
172
173 Reason:
174
175 When the signal is at a critical value, the server may configure the node to adjust to a lower power DR.
176 At this time, the server is at risk of losing uplink.
177
178
179 Solution:
180
181 Users can manually fix the DR value.
182
183
184 (% style="color:red" %)
185 **Notice:**
186
187 * User need to set Adaptive Data Rate(ADR)=0 first. otherwise device will respond to server's ADR command and change the DR according to server auto-adjustment.
188
189 * Data Rate specifies Spreading Factor. The mapping varies in different frequency bands. User can check this link for detail. [[rp2-1.0.3-lorawan-regional-parameters.pdf>>https://lora-alliance.org/resource_hub/rp2-1-0-3-lorawan-regional-parameters/]]
190
191 (% style="color:blue" %)**AT Command: AT+DR**
192
193 (% border="1" cellspacing="4" style="background-color:#f2f2f2; width:409px" %)
194 |(% style="background-color:#4f81bd; color:white; width:156px" %)**Command Example**|(% style="background-color:#4f81bd; color:white; width:147px" %)**Function**|(% style="background-color:#4f81bd; color:white; width:100px" %)**Response**
195 |(% style="width:156px" %)AT+DR=?|(% style="width:147px" %)Get the Data Rate.|(% style="width:100px" %)5(((
196 OK
197 )))
198 |(% style="width:156px" %)AT+DR=2|(% style="width:147px" %)Set the Data Rate.|(% style="width:100px" %)OK(((
199
200 )))
201
202 (% style="color:blue" %)**Downlink Command: 0x2200aaFF**
203
204 If the downlink payload=220001FF, it means setting the data rate to 1, while type code is 22 00 aa FF.
205
206 * **Example 1**: Downlink Payload: **220001FF**  ~/~/ Set AT+DR=1.
207
208 * **Example 2**: Downlink Payload: **220000FF**  ~/~/ Set AT+DR=0.
209
210 (% style="display:none" %) (%%)
211
212
213 2)  (% style="color:blue" %)**Node antenna problem**
214
215 Reason:
216
217 Node antenna is loose
218
219
220 Solution:
221
222 Please check whether the antenna interface and module interface are detached
223
224 [[image:image-20250429114526-1.png||height="429" width="303"]]
225
226
227
228 3) (% style="color:blue" %)**Gateway antenna problem**
229
230 Reason:
231 Gateway uses antenna with wrong frequency band
232
233 For example: 868-band gateway uses antenna with 915-band, which will cause the signal to be greatly reduced
234
235
236 Solution:
237
238 Please check whether the silk screen on the antenna conflicts with the frequency you set.
239
240 [[image:image-20250429115124-2.png]][[image:image-20250429115159-3.png||height="550" width="224"]]
241
242
243 4) (% style="color:blue" %)**Gateway module problem**
244
245 Reason:
246
247 Gateway uses module with wrong frequency band
248 For example: 868-band gateway uses module with 915-band, which will cause the signal to be greatly reduced
249
250
251 Solution:
252
253 Please check whether the silkscreen of the module conflicts with the frequency you set.
254
255 [[image:image-20250429115951-5.png||height="288" width="384"]][[image:image-20250429133640-7.png||height="284" width="378"]]
256
257
258 == **2. Frequency point problem** ==
259
260 Reason:
261
262 There are multiple frequency configurations in AS923/US915/AU915/CN470.
263
264 The frequency point of the gateway or server is wrong or missing.
265
266
267 Solution:
268
269 Users need to check whether the server or gateway configuration is missing or has an incorrect frequency.
270
271 The frequency range used in the dragino node is as follows
272
273
274 == **3. Frequency band problem** ==
275
276 Reason:
277
278 When there are multiple gateways, the node cannot lock the frequency band.
279
280
281 Solution:
282
283 (((
284 By default, the frequency bands US915, AU915, CN470 work in 72 frequencies. Many gateways are 8 channel gateways, and in this case, the OTAA join time and uplink schedule is long and unpredictable while the end node is hopping in 72 frequencies.
285 )))
286
287 (((
288 You can configure the end node to work in 8 channel mode by using the AT+CHE command. The 500kHz channels are always included for OTAA.
289 )))
290
291 (((
292
293 )))
294
295 (((
296 For example, in (% style="color:blue" %)**US915**(%%) band, the frequency table is as below. By default, the end node will use all channels (0~~71) for OTAA Join process. After the OTAA Join, the end node will use these all channels (0~~71) to send uplink packets.
297 )))
298
299 [[image:https://wiki.dragino.com/xwiki/bin/download/Main/User%20Manual%20for%20LoRaWAN%20End%20Nodes/LSN50%20%26%20LSN50-V2%20-%20LoRaWAN%20Sensor%20Node%20User%20Manual/WebHome/image-20220627160940-13.png?rev=1.1||alt="image-20220627160940-13.png"]]
300
301
302 (((
303 When you use the TTN V3 network, the US915 frequency bands use are:
304 )))
305
306 * (((
307 903.9 - SF7BW125 to SF10BW125
308 )))
309 * (((
310 904.1 - SF7BW125 to SF10BW125
311 )))
312 * (((
313 904.3 - SF7BW125 to SF10BW125
314 )))
315 * (((
316 904.5 - SF7BW125 to SF10BW125
317 )))
318 * (((
319 904.7 - SF7BW125 to SF10BW125
320 )))
321 * (((
322 904.9 - SF7BW125 to SF10BW125
323 )))
324 * (((
325 905.1 - SF7BW125 to SF10BW125
326 )))
327 * (((
328 905.3 - SF7BW125 to SF10BW125
329 )))
330 * (((
331 904.6 - SF8BW500
332 )))
333
334 (((
335 Because the end node is now hopping in 72 frequency, it makes it difficult for the devices to Join the TTN V3 network and uplink data. To solve this issue, you can access the device via the AT commands and run:
336 )))
337
338 (((
339 (% style="color:blue" %)**AT+CHE=2**
340 )))
341
342 (((
343 (% style="color:blue" %)**ATZ**
344 )))
345
346
347 (((
348 to set the end node to work in 8 channel mode. The device will work in Channel 8-15 & 64-71 for OTAA, and channel 8-15 for Uplink.
349 )))
350
351 (((
352 The (% style="color:blue" %)**AU915**(%%) band is similar. Below are the AU915 Uplink Channels.
353
354 [[image:https://wiki.dragino.com/xwiki/bin/download/Main/User%20Manual%20for%20LoRaWAN%20End%20Nodes/LSN50%20%26%20LSN50-V2%20-%20LoRaWAN%20Sensor%20Node%20User%20Manual/WebHome/image-20220627161124-14.png?rev=1.1||alt="image-20220627161124-14.png"]]
355
356
357 )))
358
359 = 5. Transmision on ABP Mode =
360
361
362 (((
363 In ABP mode, there is a Frame Counter Checks. With this check enabled, the server will only accept the frame with a higher counter. If you reboot the device in ABP mode, the device will start from count 0, so you won't be able to see the frame update in server.
364 )))
365
366 (((
367 So in ABP mode, first check if the packet already arrive your gateway, if the packet arrive gatewat but didn't arrive server. Please check if this is the issue.
368 )))
369
370 (((
371 To solve this, disable the Frame Counter Check will solve this issue , or reset the frame counter in the device page.
372
373 [[image:image-20240123161737-4.png||height="395" width="763"]]
374 )))
375
376 [[image:image-20240123161853-6.png||height="599" width="771"]]
377
378 Disable Frame Counter Check in ABP Mode
379
380
381 = 6. Downstream Debug =
382
383 == 6.1 How it work ==
384
385
386 LoRaWAN End node will open two receive windows to receive the downstream data. If the downstream packets arrive the end node at these receive windows, the end node will be able to get this packet and process it.
387
388 (((
389 Depends on Class A or Class C, the receive windows will be a little difference. The main difference between Class A and Class C:
390
391 * **Class A** : Suitable for Battery powered end node. Class A will save a lot of power but it can only receive downlink after each uplink
392 * **Class C**: End node can receive downlink immediately but have higher power consumption.
393
394
395 )))
396
397 [[image:image-20220531161828-1.png]]
398
399 receive windows for Class A and Class C
400
401
402 Below are the requirement for the End Device to receive the packets.
403
404 * The End Device must open the receive windows: RX1 or RX2
405
406 * The LoRaWAN server must send a downstream packet, and the gateway forward this downstream packet for this end node.
407
408 * This downstream packet must arrive to the end node while RX1 or RX2 is open.
409
410 * This packet must match the frequency of the RX1 or RX2 window.
411
412 * This packet must match the DataRate of RX1(RX1DR) or RX2 (RX2DR). (% style="color:red" %)**This is the common fail point, because different lorawan server might use different RX2DR and they don't info End Node via ADR message so cause the mismatch. If this happen, user need to change the RX2DR to the right value in end node. In OTAA, LoRaWAN Server will send the RX2DR setting in Join Accept message so the end node will auto adjust. but ABP uplink doesn't support this auto change.**
413
414 == 6.2 See Debug Info ==
415
416
417 (((
418 (% style="color:blue" %)**For LoRaWAN Server**
419 )))
420
421 (((
422 We can check if there is downlink message for this end node, use TTN for example:
423 )))
424
425 (((
426 Configure a downlink to the end device
427
428 [[image:image-20240129152412-8.png||height="486" width="1206"]]
429 )))
430
431
432 (((
433 Set a downstream in TTN and see it is sent
434 )))
435
436 (% style="color:red" %)**Note: After the downlink command is successfully sent from the platform to the node, the downlink command is executed only after the platform receives the next uplink package from the node.**
437
438
439 (((
440 This downlink info will then pass to the gateway downlink list. and the DR which is used (SF7BW500) in US915 is DR5.
441 )))
442
443 [[image:image-20240129152049-7.png||height="463" width="1166"]]
444
445 (((
446 Gateway Traffic can see this downlink info
447 )))
448
449
450
451 (((
452 (% style="color:blue" %)**For LoRaWAN Gateway**
453 )))
454
455 (((
456 When the downlink packet appear on the traffic of Gateway page. The LoRaWAN gateway can get it from LoRaWAN server and transmit it. In Dragino Gateway, this can be checked by running "logread -f" in the SSH console. and see below:
457 )))
458
459 [[image:image-20240129154321-9.png]]
460
461 (((
462 Gateway Sent out this packet
463 )))
464
465
466
467 (((
468 (% style="color:blue" %)**For End Node**
469 )))
470
471 (((
472 we can use AT Command (AT+CFG) to check the RX1 configure and RX2 configure. as below:
473 )))
474
475 (((
476 * (% style="color:#037691" %)**AT+RX2FQ=869525000**  (%%) **~-~-->**  The RX2 Window frequency
477
478 * (% style="color:#037691" %)**AT+RX2DR=3**          (%%) **~-~-->**  The RX2 DataRate
479
480 * (% style="color:#037691" %)**AT+RX1DL=1000**       (%%) ** ~-~-->**  Receive Delay 1
481
482 * (% style="color:#037691" %)**AT+RX2DL=2000**       (%%) **~-~--> ** Receive Delay 2
483 )))
484
485 (((
486 (% style="color:blue" %)**when the device running, we can see below info:**
487 )))
488
489 {{{ [12502]***** UpLinkCounter= 0 *****
490 [12503]TX on freq 868500000 Hz at DR 0
491 [13992]txDone
492 [15022]RX on freq 868500000 Hz at DR 0 --> RX1 window open at frequency: 868500000, DR0, after 15022-13992= 1030ms of txdone
493 [15222]rxTimeOut --> no packet arrive in RX1 window. (duration: 200ms)
494 [15987]RX on freq 869525000 Hz at DR 3 --> RX2 window open at frequency: 869525000, DR3, after 15987-13992= 1995ms of txdone
495 [16027]rxTimeOut --> no packet arrive in RX2 window. (duration: 40 ms)}}}
496
497 (((
498
499
500
501 )))
502
503 (((
504 (% style="color:blue" %)**Another message:**
505 )))
506
507 {{{ [12502]***** UpLinkCounter= 0 *****
508 [12503]TX on freq 868100000 Hz at DR 0
509 [13992]txDone
510 [15022]RX on freq 868100000 Hz at DR 0
511 [15222]rxTimeOut
512 [15987]RX on freq 869525000 Hz at DR 3
513 [16185]rxDone --> We have got the downstream packet.
514 Rssi= -64
515 Receive data
516 1:0012345678}}}
517
518
519 == 6.3 If problem doesn't solve ==
520
521
522 (% style="color:red" %)**If user has checked below steps and still can't solve the problem, please send us (support @ dragino.com) the sceenshots for each step to check. They include:**
523
524 * End node console to show the transmit freuqency and DR.
525
526 * Gateway (from gateway UI) traffic to show the packet got from end node and receive from Server.
527
528 * Gateway traffic (from server UI) to shows the data exchange between gateway and server.
529
530 * End Node traffic (from server UI) to shows end node activity in server.
531
532 = 7. Downlink Issue ~-~- Packet REJECTED, unsupported frequency =
533
534
535 (((
536 In LoRaWAN, the gateway will use the frequency specify by the server to transmit a packet as downlink purpose. Each Frequency band has different downlink frequency. and the gateway has a frequency range limited to transmit downlink.
537 )))
538
539 (((
540
541 )))
542
543 (((
544 So if the LoRaWAN server is an AS923 server which ask the gateway to transmit at 923.2Mhz frequency, but the gateway is IN868 frequency band (support 865~~867Mhz to transmit). In the gateway log it will show something like below:
545 )))
546
547 {{{Sat Nov 21 08:04:17 2020 daemon.info lora_pkt_fwd[1680]: ERROR~ Packet REJECTED, unsupported frequency - 923200000 (min:865000000,max:867000000)}}}
548
549 (((
550
551 )))
552
553 (((
554 In this case, please double check the gateway frequency and the server frequency band.
555 )))
556
557
558 = 8. Decrypt a LoRaWAN Packet =
559
560
561 (% style="color:blue" %)**1. LHT65N End device configure:**
562
563 **Change to ABP Mode:  AT+NJM=0**
564
565 **Change to fix frequency:  ​​​​AT+CHE=1**
566
567
568 **AT+CFG(Print configuration):**
569
570 [[image:image-20240129170603-7.png||height="697" width="545"]][[image:image-20240129163741-3.png||height="694" width="565"]]
571
572
573
574 **Configuration: **
575
576 [[image:image-20240129164219-4.png||height="612" width="440"]]
577
578
579
580 (% style="color:blue" %)**2. In LPS8-v2, configure to receive above message**
581
582 [[image:image-20240129164326-5.png||height="506" width="1114"]]
583
584
585 In LPS8-v2 console, we can see the Base64 receive are:
586
587 [[image:image-20240129170137-6.png||height="459" width="1116"]]
588
589
590
591 (% style="color:blue" %)**3. Decode the info in CMD(Command prompt window)**
592
593 LoRa packet Base64 format:  QP~/~/~/~/+AFQACZv8Hjmc8gFTAkhMzU+75 **(from LPS8-v2)**
594
595 Then the instructions and format parsed in SecureCRT are:  ./node_modules/.bin/lora-packet-decode ~-~-base64 QP~/~/~/~/+AFQACZv8Hjmc8gFTAkhMzU+75
596
597
598 **Step1: Open CMD, Enter the gateway IP and port.(ssh root@gateway IP -p 22)**
599
600 [[image:image-20240129190752-17.png||height="338" width="901"]]
601
602 [[image:image-20240129191937-21.png||height="450" width="901"]]
603
604
605 **Step2: Enter the command to download the LoRa parsing package.(npm install lora-packet)**
606
607 [[image:image-20240129192239-22.png||height="416" width="902"]]
608
609 [[image:image-20240129192549-23.png||height="459" width="898"]]
610
611
612 **Step3: Parse the gateway raw payload.(./node_modules/.bin/lora-packet-decode ~-~-base64 QP~/~/~/~/+AFQACZv8Hjmc8gFTAkhMzU+75)**
613
614
615
616
617 [[image:image-20240129192908-24.png||height="477" width="907"]]
618
619
620 [[image:image-20240129192954-25.png||height="485" width="916"]]
621
622
623
624
625
626
627
628 = 9. Why I see uplink 0x00 periodically on the LHT65 v1.8 firmware =
629
630
631 Since firmware v1.8, LHT65 will send MAC command to request time, in the case if DR only support max 11 bytes, this MAC command will be bundled to a separate uplink payload with 0x00.
632
633
634 = 10. Why do I see a "MIC Mismatch" error message from the server? =
635
636
637 (((
638 1)  If the user receives a "MIC Mismatch" message after registering the node on the server.
639 )))
640
641 (((
642 It is likely that the user filled in the wrong APPKEY when registering the node. Many users fill in "APPSKEY".
643 )))
644
645 * (((
646 Please note the distinction between "APPKEY" and "APPSKEY".
647 )))
648
649 (((
650 2)If the node works on the server for a period of time, the device stops working and receives a "MIC Mismatch" message.
651 )))
652
653 (((
654 The user needs a USB-TTL adapter to connect the serial port to modify the node APPKEY.
655 )))
656
657 * (((
658 If a node is registered with multiple servers, it may also cause the "mic mismatch" error.
659 )))
660
661 (% class="wikigeneratedid" %)
662 3)Wrong Regional Parameters version selected
663 We generally use versions above 1.0.2
664
665 (% class="wikigeneratedid" %)
666 [[image:image-20230322163227-1.png]]
667
668 (% class="wikigeneratedid" %)
669 4)We have had cases where it was automatically fixed the next day despite no manual changes, probably a server side issue
670
671
672 = 11. Why I got the payload only with "0x00" or "AA~=~="? =
673
674
675 (% style="color:blue" %)**Why sensor sends 0x00?**
676
677 For US915, AU915 or AS923 frequencies, the max payload lenght is 11 bytes for DR0. Some times sensor needs to send MAC command to server, because the payload is 11 bytes, The MAC command + Payload will exceed 11 bytes and LoRaWAN server will ignore the uplink. In this case, Sensor will send two uplinks together: one uplink is the payload without MAC command, another uplink is **0x00 payload + MAC Command.**  For the second uplink, in the server side, it will shows the payload is 0x00. Normally, there are several case this will happen.
678
679 **Possible Case 1**:
680
681 Sensor has ADR=1 enable and sensor need to reply server MAC command (ADR request) while sensor has DR=0.
682
683
684 **Possible Case 2:**
685
686 For the sensor which has Datalog Feature enable, the sensor will send TimeRequest MAC Command to sync the time. This Time Request will be sent once Sensor Join Network and Every 10 days. While they send such command with DR=0, sensor will send this command with 0x00 payload.
687
688
689 (% style="color:blue" %)**How to solve:**
690
691 Solution:
692
693 ~1. Use the decoder to filter out this 0x00 packet. (**Recommand**)
694
695 2. Data rate changed from DR3 to DR5, increasing upload byte length
696 AT+ADR=0
697 AT+DR=3
698
699 Downlink:
700
701 [[http:~~/~~/wiki.dragino.com/xwiki/bin/view/Main/End%20Device%20AT%20Commands%20and%20Downlink%20Command/#H7.4DataRate>>http://wiki.dragino.com/xwiki/bin/view/Main/End%20Device%20AT%20Commands%20and%20Downlink%20Command/#H7.4DataRate]]
702
703 Some node decoders may not have the filter function, or you need decoders of other servers and formats. Please send an email to [[support@dragino.com>>mailto:support@dragino.com]]
704
705
706 = 12. Why my Dev EUI and APP EUI is 0x000000000000, how to solve? =
707
708
709 (((
710 It is possible the keys is erased during upgrading of firmware. and the console output shows below after AT+CFG
711 )))
712
713 (((
714 AT+APPKEY=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
715 )))
716
717 (((
718 AT+NWKSKEY=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
719 )))
720
721 (((
722 AT+APPSKEY=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
723 )))
724
725 (((
726 AT+APPEUI=00 00 00 00 00 00 00 00
727 )))
728
729 (((
730
731 )))
732
733 (((
734 You can get the keys from the box sticker or send mail to Dragino Support to check keys with the provided SN number.
735 )))
736
737 (((
738 You can rewrites the keys by running commands in AT Console
739
740
741 )))
742
743 (((
744 **For example:**
745 )))
746
747 (((
748 AT+APPKEY=85 41 47 20 45 58 28 14 16 82 A0 F0 80 0D DD EE
749 )))
750
751 (((
752 AT+NWKSKEY=AA CC B0 20 30 45 37 32 14 1E 14 93 E2 3B 20 11
753 )))
754
755 (((
756 AT+APPSKEY=11 23 02 20 30 20 30 60 80 20 20 30 30 20 10 10
757 )))
758
759 (((
760 AT+APPEUI=2C 45 47 E3 24 12 23 24
761 )))
762
763 (((
764 (Any combination of 16 bit codes can be used)
765
766
767 = 13. I set my device is LoRaWAN Class C mode, why I still see Class A after boot? =
768 )))
769
770
771 Class C only refers to status after OTAA Join successfully. The OTAA Join Process will use Class A mode.
772
773
774 = 14. Why it takes longer time for OTAA joined in US915/CN470/AU915 band? =
775
776
777 In US915, AU915 or CN470 frequency band, there are 8 sub-bands, totally 72 channels. and LoRaWAN server normally use only one sub-band, for example Sub-band 2 in TTN. The gateway also configured to Sub-band 2 and cover eight channels in this sub-band. If the end node transfer data in Sub-band 2, it will reach to gateway and to the LoRaWAN server. If the end node transfer packets in other sub-bands, for example sub-band 1, the packet won't arrive both gateway or LoRaWAN server.
778
779
780 In Dragino Sensors old version firmware (before early 2022), the sub-band is fixed the sub-band to 2 , but this cause a problem, the end node is hard to use in other subband and need program. So the new logic is as below:
781
782 We have improved this, the end node will use frequency 1 from sub-band1, then frequency 1 from sub-band2, then frequency 1 from sub-band3, etc to process the OTAA join, in this case, in this case, the end node can support LoRaWAN servers with different sub-bands. To make sure the end node will only transmit the proper sub-band after OTAA Joined successfully, the end node will:
783
784 * (((
785 Check what sub-band the LoRaWAN server ask from the OTAA Join Accept message and switch to that sub-band.
786 )))
787 * (((
788 Use the Join successful sub-band if the server doesn't include sub-band info in the OTAA Join Accept message (TTN v2 doesn't include).
789 )))
790
791 This change will make the activation time a little longer but make sure the device can be used in any sub-band.
792
793
794 Below is a photo to show why it takes longer time for OTAA Join. We can see in 72 channels mode, why it takes more time to join success. If users want to have faster OTAA Join success, he can change default CHE to the sub-band he uses.
795
796
797 [[image:image-20221215223215-1.png||height="584" width="1280"]]