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Wiki source code of LoRaWAN Communication Debug

Version 37.2 by Xiaoling on 2022/12/16 10:46
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1 **~ Table of Contents:**
2
3 {{toc/}}
4
5
6
7 = 1.(% style="display:none" %) (%%) OTAA Join Process Debug =
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 * Gateway (from gateway UI) traffic to show the packet got from end node and receive from Server. (If possible)
15 * Gateway traffic (from server UI) to shows the data exchange between gateway and server. (Normaly possible)
16 * End Node traffic (from server UI) to shows end node activity in server. (Normaly possible)
17 * 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)
18
19 (% style="color:blue" %)**1. End Device Join Screen shot, we can check:**
20
21 * If the device is sending join request to server?
22 * What frequency the device is sending?
23
24 [[image:image-20220526164956-15.png||height="591" width="1153"]]
25
26 Console Output from End device to see the transmit frequency
27
28
29
30 (% style="color:blue" %)**2. Gateway packet traffic in gateway web or ssh. we can check:**
31
32 * If the gateway receive the Join request packet from sensor? (If this fail, check if the gateway and sensor works on the match frequency)
33 * If the gateway gets the Join Accept message from server and transmit it via LoRa?
34
35 [[image:image-20220526163608-2.png]]
36
37 Console Output from Gateway to see packets between end node and server.
38
39
40
41 (% style="color:blue" %)**3. Gateway Traffic Page in LoRaWAN Server**
42
43 * If the Join Request packet arrive the gateway traffic in server? If not, check the internet connection and gateway LoRaWAN server settings.
44 * If the server send back a Join Accept for the Join Request? if not, check if the keys from the device match the keys you put in the server, or try to choose a different server route for this end device.
45 * 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.
46
47 [[image:image-20220526163633-3.png]]
48
49 The Traffic for the End node in the server, use TTN as example
50
51
52
53 (% style="color:blue" %)**4. Data Page in LoRaWAN server**
54
55 * 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.
56
57 [[image:image-20220526163704-4.png]]
58
59 The data for the end device set in server
60
61
62 [[image:image-20220526163732-5.png]]
63
64 Check if OTAA Keys match the keys in device
65
66
67 = 2. Notice of US915/CN470/AU915 Frequency band =
68
69
70 (((
71 If user has problem to work with lorawan server in band US915/AU915/CN470, he can check:
72 )))
73
74 * (((
75 What **sub-band** the server support ?
76 )))
77 * (((
78 What is the **sub-band** the gateway support ?
79 )))
80 * (((
81 What is the **sub-band** the end node is using ?
82 )))
83
84 (((
85 All of above should match so End Node can properly Join the server and don't have packet lost.
86 )))
87
88 (((
89
90 )))
91
92 (((
93 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.
94 )))
95
96 (((
97
98 )))
99
100 (((
101 Here are the freuqency tables for these bands as reference:
102 )))
103
104 [[image:image-20220526163801-6.png]]
105
106 US915 Channels
107
108
109 [[image:image-20220526163926-7.png]]
110
111 AU915 Channels
112
113
114 [[image:image-20220526163941-8.png]]
115
116 (((
117 CN470 Channels
118
119
120 )))
121
122 (((
123 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.
124 )))
125
126 [[image:image-20220526164052-9.png]]
127
128 (((
129 TTN FREQUENCY PLAN
130
131 (% style="display:none" %) (%%)
132 )))
133
134 (((
135 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. )
136 )))
137
138 (% style="display:none" %) (%%)
139
140 = 3. Why i see data lost/unperiocially uplink data? Even the signal strength is good =
141
142
143 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:
144
145 * (% 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.
146
147 * (% 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.
148
149 * (% 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.
150
151 (((
152 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.
153 )))
154
155
156 (((
157 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.
158 )))
159
160
161 = 4. Transmision on ABP Mode =
162
163
164 (((
165 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.
166 )))
167
168 (((
169 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.
170 )))
171
172 (((
173 To solve this, disable the Frame Counter Check will solve this issue , or reset the frame counter in the device page.
174 )))
175
176 [[image:image-20220526164508-10.png]]
177
178 Disable Frame Counter Check in ABP Mode
179
180
181 = 5. Downstream Debug =
182
183 == 5.1 How it work ==
184
185
186 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.
187
188 (((
189 Depends on Class A or Class C, the receive windows will be a little difference,
190 )))
191
192 [[image:image-20220531161828-1.png]]
193
194 receive windows for Class A and Class C
195
196
197 Below are the requirement for the End Device to receive the packets.
198
199 * The End Device must open the receive windows: RX1 or RX2
200
201 * The LoRaWAN server must send a downstream packet, and the gateway forward this downstream packet for this end node.
202
203 * This downstream packet must arrive to the end node while RX1 or RX2 is open.
204
205 * This packet must match the frequency of the RX1 or RX2 window.
206
207 * 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.**
208
209
210
211 == 5.2 See Debug Info ==
212
213
214 (((
215 (% style="color:blue" %)**For LoRaWAN Server**
216 )))
217
218 (((
219 We can check if there is downlink message for this end node, use TTN for example:
220 )))
221
222 (((
223 Configure a downstream to the end device
224 )))
225
226 [[image:image-20220526164623-12.png]]
227
228 (((
229 Set a downstream in TTN and see it is sent
230 )))
231
232
233 (((
234 This downstream info will then pass to the gateway downstream list. and include the DR which is used (SF9BW125) in EU868 is DR3
235 )))
236
237 [[image:image-20220526164650-13.png]]
238
239 (((
240 Gateway Traffic can see this downstream info
241 )))
242
243
244
245 (((
246 (% style="color:blue" %)**For LoRaWAN Gateway**
247 )))
248
249 (((
250 When the downstream packet appear on the traffic of Gateway page. The LoRaWAN gateway can get it from LoRaWAN server and transmit it. In Dragion Gateway, this can be checked by runinng "logread -f" in the SSH console. and see below:
251 )))
252
253 [[image:image-20220526164734-14.png]]
254
255 (((
256 Gateway Sent out this packet
257 )))
258
259
260
261 (((
262 (% style="color:blue" %)**For End Node**
263 )))
264
265 (((
266 we can use AT Command (AT+CFG) to check the RX1 configure and RX2 configure. as below:
267 )))
268
269 (((
270 (% style="color:#037691" %)**AT+RX2FQ=869525000**  (%%) **~-~-->**  The RX2 Window frequency
271 (% style="color:#037691" %)**AT+RX2DR=3**          (%%) **~-~-->**  The RX2 DataRate
272 (% style="color:#037691" %)**AT+RX1DL=1000**       (%%) ** ~-~-->**  Receive Delay 1
273 (% style="color:#037691" %)**AT+RX2DL=2000**       (%%) **~-~--> ** Receive Delay 2
274
275
276
277 )))
278
279 (((
280 (% style="color:blue" %)**when the device running, we can see below info:**
281 )))
282
283 {{{ [12502]***** UpLinkCounter= 0 *****
284 [12503]TX on freq 868500000 Hz at DR 0
285 [13992]txDone
286 [15022]RX on freq 868500000 Hz at DR 0 --> RX1 window open at frequency: 868500000, DR0, after 15022-13992= 1030ms of txdone
287 [15222]rxTimeOut --> no packet arrive in RX1 window. (duration: 200ms)
288 [15987]RX on freq 869525000 Hz at DR 3 --> RX2 window open at frequency: 869525000, DR3, after 15987-13992= 1995ms of txdone
289 [16027]rxTimeOut --> no packet arrive in RX2 window. (duration: 40 ms)}}}
290
291 (((
292
293
294
295 )))
296
297 (((
298 (% style="color:blue" %)**Another message:**
299 )))
300
301 {{{ [12502]***** UpLinkCounter= 0 *****
302 [12503]TX on freq 868100000 Hz at DR 0
303 [13992]txDone
304 [15022]RX on freq 868100000 Hz at DR 0
305 [15222]rxTimeOut
306 [15987]RX on freq 869525000 Hz at DR 3
307 [16185]rxDone --> We have got the downstream packet.
308 Rssi= -64
309 Receive data
310 1:0012345678}}}
311
312
313 == 5.3 If problem doesn't solve ==
314
315
316 (% 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:**
317
318 * End node console to show the transmit freuqency and DR.
319 * Gateway (from gateway UI) traffic to show the packet got from end node and receive from Server.
320 * Gateway traffic (from server UI) to shows the data exchange between gateway and server.
321 * End Node traffic (from server UI) to shows end node activity in server.
322
323
324
325 = 6. Downlink Issue ~-~- Packet REJECTED, unsupported frequency =
326
327
328 (((
329 In LoRaWAN, the gatewat 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.
330 )))
331
332 (((
333
334 )))
335
336 (((
337 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:
338 )))
339
340 {{{Sat Nov 21 08:04:17 2020 daemon.info lora_pkt_fwd[1680]: ERROR~ Packet REJECTED, unsupported frequency - 923200000 (min:865000000,max:867000000)}}}
341
342 (((
343
344 )))
345
346 (((
347 In this case, please double check the gateway frequency and the server frequency band.
348 )))
349
350
351 = 7. Decrypt a LoRaWAN Packet =
352
353
354 (% style="color:blue" %)**1. LHT65 End device configure:**
355
356 **Change to ABP Mode:  AT+NJM=0**
357 **Change to fix frequency:  AT+CHS=904900000**
358 **Change to fix DR:  AT+DR=0**
359
360
361 [[image:image-20220526165525-16.png]]
362
363
364
365 (% style="color:blue" %)**2. In LG02 , configure to receive above message**
366
367 [[image:image-20220526165612-17.png]]
368
369
370 In LG02 console, we can see the hex receive are:
371
372 [[image:image-20220526171112-21.png]]
373
374
375
376 (% style="color:blue" %)**3. Decode the info in web**
377
378 [[https:~~/~~/lorawan-packet-decoder-0ta6puiniaut.runkit.sh>>url:https://lorawan-packet-decoder-0ta6puiniaut.runkit.sh/]]
379
380 Need these three fields:
381
382 LoRa packet hex format: 40c1190126800100024926272bf18bbb6341584e27e23245 (from LG02)
383
384 AT+NWKSKEY=00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 11 (End node Network Session Key)
385
386 AT+APPSKEY=00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 11 (End Node App Session Key)
387
388
389 [[https:~~/~~/lorawan-packet-decoder-0ta6puiniaut.runkit.sh/?data=40c1190126800100024926272bf18bbb6341584e27e23245&nwkskey=00000000000000000000000000000111&appskey=00000000000000000000000000000111>>url:https://lorawan-packet-decoder-0ta6puiniaut.runkit.sh/?data=40c1190126800100024926272bf18bbb6341584e27e23245&nwkskey=00000000000000000000000000000111&appskey=00000000000000000000000000000111]]
390
391 [[image:image-20220526171029-20.png]]
392
393 (((
394 The FRMPayload is the device payload.
395 )))
396
397
398 = 8. Why i see uplink 0x00 periodcally on the LHT65 v1.8 firmware =
399
400
401 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.
402
403
404 = 9. Why do I see a "MIC Mismatch" error message from the server? =
405
406
407 (((
408 1)  If the user receives a "MIC Mismatch" message after registering the node on the server.
409 )))
410
411 (((
412 It is likely that the user filled in the wrong APPKEY when registering the node. Many users fill in "APPSKEY".
413 )))
414
415 * (((
416 Please note the distinction between "APPKEY" and "APPSKEY".
417 )))
418
419 (((
420 2）If the node works on the server for a period of time, the device stops working and receives a "MIC Mismatch" message.
421 )))
422
423 (((
424 The user needs a USB-TTL adapter to connect the serial port to modify the node APPKEY.
425 )))
426
427 * (((
428 If a node is registered with multiple servers, it may also cause the "mic mismatch" error.
429
430
431
432 )))
433
434 = 10. Why i got the payload only with "0x00" or "AA~=~="? =
435
436
437 **Why this happen:**
438
439 For US915, AU915 or AS923 frequencies.It is possible because: .
440
441 When using the frequency mentioned above, the server sometimes adjusts the Data Rate (DR) of the node, because the end node has Adaptive Data Rate (ADR) Enabled.
442
443 When the server adjusts end node data rate to 0, the maximum payload length is 11 bytes. The server sometimes sends an ADR packet to the end node, and the node will reply to the server after receiving the ADR packet, but the number of payload bytes exceeds the limit, so it will send a normal uplink packet, and following an additional 00 data packet to handle this MAC command response.
444
445
446 **How to solve:**
447
448 Solution: Use the decoder to filter out this 0x00 packet.
449
450 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]]
451
452
453 = 11. Why my Dev EUI and APP EUI is 0x000000000000, how to solve? =
454
455
456 (((
457 It is possible the keys is erased during upgrading of firmware. and the console output shows below after AT+CFG
458 )))
459
460 (((
461 AT+APPKEY=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
462 )))
463
464 (((
465 AT+NWKSKEY=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
466 )))
467
468 (((
469 AT+APPSKEY=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
470 )))
471
472 (((
473 AT+APPEUI=00 00 00 00 00 00 00 00
474 )))
475
476 (((
477
478 )))
479
480 (((
481 You can get the keys from the box sticker or send mail to Dragino Support to check keys with the provided SN number.
482 )))
483
484 (((
485 You can rewrites the keys by running commands in AT Console
486
487
488 )))
489
490 (((
491 **For example：**
492 )))
493
494 (((
495 AT+APPKEY=85 41 47 20 45 58 28 14 16 82 A0 F0 80 0D DD EE
496 )))
497
498 (((
499 AT+NWKSKEY=AA CC B0 20 30 45 37 32 14 1E 14 93 E2 3B 20 11
500 )))
501
502 (((
503 AT+APPSKEY=11 23 02 20 30 20 30 60 80 20 20 30 30 20 10 10
504 )))
505
506 (((
507 AT+APPEUI=2C 45 47 E3 24 12 23 24
508 )))
509
510 (((
511 (Any combination of 16 bit codes can be used）
512
513
514 = 12. I set my device is LoRaWAN Class C mode, why i still see Class A after boot? =
515 )))
516
517
518 Class C only refers to status after OTAA Join successfully. The OTAA Join Process will use Class A mode.
519
520
521 = 13. Why it takes longer time for OTAA joined in US915/CN470/AU915 band? =
522
523
524 In US915, AU915 or CN470 frequency band, there are 8 subbands, totally 72 channels. and LoRaWAN server normally use only one sub-band, for example Subband 2 in TTN. The gateway also configured to Subband 2 and cover eight channels in this subband. If the end node transfer data in Subband 2, it will reach to gateway and to the LoRaWAN server. If the end node transfer packets in other subbands, for example subband 1, the packet won't arrive both gateway or LoRaWAN server.
525
526
527 In Dragino Sensors old version firmware (before early 2022), the subband is fixed the subband 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:
528
529 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 subbands. To make sure the end node will only transmit the proper sub-band after OTAA Joined successfully, the end node will:
530
531 * (((
532 Check what sub-band the LoRaWAN server ask from the OTAA Join Accept message and switch to that subband
533 )))
534 * (((
535 Use the Join successful sub-band if the server doesn't include subband info in the OTAA Join Accept message ( TTN v2 doesn't include)
536 )))
537
538 This change will make the activation time a littler longer but make sure the device can be used in any subband.
539
540
541 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 subband he use.
542
543
544 [[image:image-20221215223215-1.png||height="584" width="1280"]]
545
546 (% class="wikigeneratedid" %)
547