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Wiki source code of LoRaWAN Communication Debug

Version 34.1 by Edwin Chen on 2022/10/19 23:14
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1 **~ Table of Contents:**
2
3 {{toc/}}
4
5
6
7 = 1. 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]]
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 (% style="color:blue" %)**3. Gateway Traffic Page in LoRaWAN Server**
41
42 * If the Join Request packet arrive the gateway traffic in server? If not, check the internet connection and gateway LoRaWAN server settings.
43 * 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.
44 * 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.
45
46 [[image:image-20220526163633-3.png]]
47
48 The Traffic for the End node in the server, use TTN as example
49
50
51 (% style="color:blue" %)**4. Data Page in LoRaWAN server**
52
53 * 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.
54
55 [[image:image-20220526163704-4.png]]
56
57 The data for the end device set in server
58
59 [[image:image-20220526163732-5.png]]
60
61 Check if OTAA Keys match the keys in device
62
63
64
65 = 2. Notice of US915/CN470/AU915 Frequency band =
66
67
68 (((
69 If user has problem to work with lorawan server in band US915/AU915/CN470, he can check:
70 )))
71
72 * (((
73 What **sub-band** the server support ?
74 )))
75 * (((
76 What is the **sub-band** the gateway support ?
77 )))
78 * (((
79 What is the **sub-band** the end node is using ?
80 )))
81
82 (((
83 All of above should match so End Node can properly Join the server and don't have packet lost.
84 )))
85
86 (((
87
88 )))
89
90 (((
91 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.
92 )))
93
94 (((
95
96 )))
97
98 (((
99 Here are the freuqency tables for these bands as reference:
100 )))
101
102 [[image:image-20220526163801-6.png]]
103
104 US915 Channels
105
106 [[image:image-20220526163926-7.png]]
107
108 AU915 Channels
109
110
111 [[image:image-20220526163941-8.png]]
112
113 (((
114 CN470 Channels
115
116
117 )))
118
119 (((
120 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.
121 )))
122
123 [[image:image-20220526164052-9.png]]
124
125 (((
126 TTN FREQUENCY PLAN
127
128
129 )))
130
131 (((
132 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. )
133 )))
134
135
136
137 = 3. Why i see data lost/unperiocially uplink data? Even the signal strength is good =
138
139
140 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:
141
142 * **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.
143 * **Gateway** ~-~-> Use Sub-band2 (Channel 8,9,10,11,12,13,14,15) for Dragino Gateway. this is the default settings for dragino sensors.
144 * **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.
145
146 (((
147 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.
148 )))
149
150 (((
151
152 )))
153
154 (((
155 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.
156 )))
157
158
159
160 = 4. Transmision on ABP Mode =
161
162
163 (((
164 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.
165 )))
166
167 (((
168
169 )))
170
171 (((
172 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.
173 )))
174
175 (((
176
177 )))
178
179 (((
180 To solve this, disable the Frame Counter Check will solve this issue , or reset the frame counter in the device page.
181 )))
182
183 [[image:image-20220526164508-10.png]]
184
185 Disable Frame Counter Check in ABP Mode
186
187
188
189 = 5. Downstream Debug =
190
191 == 5.1 How it work ==
192
193
194 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.
195
196 (((
197 Depends on Class A or Class C, the receive windows will be a little difference,
198 )))
199
200 [[image:image-20220531161828-1.png]]
201
202 receive windows for Class A and Class C
203
204
205 Below are the requirement for the End Device to receive the packets.
206
207 * The End Device must open the receive windows: RX1 or RX2
208 * The LoRaWAN server must send a downstream packet, and the gateway forward this downstream packet for this end node.
209 * This downstream packet must arrive to the end node while RX1 or RX2 is open.
210 * This packet must match the frequency of the RX1 or RX2 window.
211 * 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.**
212
213
214 == 5.2 See Debug Info ==
215
216
217 (((
218 (% style="color:blue" %)**For LoRaWAN Server**
219 )))
220
221 (((
222 We can check if there is downlink message for this end node, use TTN for example:
223 )))
224
225 (((
226 Configure a downstream to the end device
227 )))
228
229 [[image:image-20220526164623-12.png]]
230
231 (((
232 Set a downstream in TTN and see it is sent
233 )))
234
235
236 (((
237 This downstream info will then pass to the gateway downstream list. and include the DR which is used (SF9BW125) in EU868 is DR3
238 )))
239
240 [[image:image-20220526164650-13.png]]
241
242 (((
243 Gateway Traffic can see this downstream info
244 )))
245
246
247
248 (((
249 (% style="color:blue" %)**For LoRaWAN Gateway**
250 )))
251
252 (((
253 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:
254 )))
255
256 [[image:image-20220526164734-14.png]]
257
258 (((
259 Gateway Sent out this packet
260 )))
261
262
263
264 (((
265 (% style="color:blue" %)**For End Node**
266 )))
267
268 (((
269 we can use AT Command (AT+CFG) to check the RX1 configure and RX2 configure. as below:
270 )))
271
272 (((
273 (% style="color:#037691" %)**AT+RX2FQ=869525000**  (%%) **~-~-->**  The RX2 Window frequency
274 (% style="color:#037691" %)**AT+RX2DR=3**          (%%) **~-~-->**  The RX2 DataRate
275 (% style="color:#037691" %)**AT+RX1DL=1000**       (%%) ** ~-~-->**  Receive Delay 1
276 (% style="color:#037691" %)**AT+RX2DL=2000**       (%%) **~-~--> ** Receive Delay 2
277
278
279
280 )))
281
282 (((
283 (% style="color:blue" %)**when the device running, we can see below info:**
284 )))
285
286 {{{ [12502]***** UpLinkCounter= 0 *****
287 [12503]TX on freq 868500000 Hz at DR 0
288 [13992]txDone
289 [15022]RX on freq 868500000 Hz at DR 0 --> RX1 window open at frequency: 868500000, DR0, after 15022-13992= 1030ms of txdone
290 [15222]rxTimeOut --> no packet arrive in RX1 window. (duration: 200ms)
291 [15987]RX on freq 869525000 Hz at DR 3 --> RX2 window open at frequency: 869525000, DR3, after 15987-13992= 1995ms of txdone
292 [16027]rxTimeOut --> no packet arrive in RX2 window. (duration: 40 ms)}}}
293
294 (((
295
296
297
298 )))
299
300 (((
301 (% style="color:blue" %)**Another message:**
302 )))
303
304 {{{ [12502]***** UpLinkCounter= 0 *****
305 [12503]TX on freq 868100000 Hz at DR 0
306 [13992]txDone
307 [15022]RX on freq 868100000 Hz at DR 0
308 [15222]rxTimeOut
309 [15987]RX on freq 869525000 Hz at DR 3
310 [16185]rxDone --> We have got the downstream packet.
311 Rssi= -64
312 Receive data
313 1:0012345678}}}
314
315
316
317 == 5.3 If problem doesn't solve ==
318
319
320 (% 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:**
321
322 * End node console to show the transmit freuqency and DR.
323 * Gateway (from gateway UI) traffic to show the packet got from end node and receive from Server.
324 * Gateway traffic (from server UI) to shows the data exchange between gateway and server.
325 * End Node traffic (from server UI) to shows end node activity in server.
326
327
328 = 6. Downlink Issue ~-~- Packet REJECTED, unsupported frequency =
329
330
331 (((
332 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.
333 )))
334
335 (((
336
337 )))
338
339 (((
340 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:
341 )))
342
343 {{{Sat Nov 21 08:04:17 2020 daemon.info lora_pkt_fwd[1680]: ERROR~ Packet REJECTED, unsupported frequency - 923200000 (min:865000000,max:867000000)}}}
344
345 (((
346
347 )))
348
349 (((
350 In this case, please double check the gateway frequency and the server frequency band.
351 )))
352
353
354
355 = 7. Decrypt a LoRaWAN Packet =
356
357
358 (% style="color:blue" %)**1. LHT65 End device configure:**
359
360 **Change to ABP Mode:  AT+NJM=0**
361 **Change to fix frequency:  AT+CHS=904900000**
362 **Change to fix DR:  AT+DR=0**
363
364
365 [[image:image-20220526165525-16.png]]
366
367
368
369 (% style="color:blue" %)**2. In LG02 , configure to receive above message**
370
371 [[image:image-20220526165612-17.png]]
372
373
374 In LG02 console, we can see the hex receive are:
375
376 [[image:image-20220526171112-21.png]]
377
378
379
380 (% style="color:blue" %)**3. Decode the info in web**
381
382 [[https:~~/~~/lorawan-packet-decoder-0ta6puiniaut.runkit.sh>>url:https://lorawan-packet-decoder-0ta6puiniaut.runkit.sh/]]
383
384 Need these three fields:
385
386 LoRa packet hex format: 40c1190126800100024926272bf18bbb6341584e27e23245 (from LG02)
387
388 AT+NWKSKEY=00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 11 (End node Network Session Key)
389
390 AT+APPSKEY=00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 11 (End Node App Session Key)
391
392
393 [[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]]
394
395 [[image:image-20220526171029-20.png]]
396
397 (((
398 The FRMPayload is the device payload.
399 )))
400
401
402
403 = 8. Why i see uplink 0x00 periodcally on the LHT65 v1.8 firmware =
404
405
406 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.
407
408
409
410 = 9. Why do I see a "MIC Mismatch" error message from the server? =
411
412
413 (((
414 1)  If the user receives a "MIC Mismatch" message after registering the node on the server.
415 )))
416
417 (((
418 It is likely that the user filled in the wrong APPKEY when registering the node. Many users fill in "APPSKEY".
419 )))
420
421 * (((
422 Please note the distinction between "APPKEY" and "APPSKEY".
423 )))
424
425 (((
426 2）If the node works on the server for a period of time, the device stops working and receives a "MIC Mismatch" message.
427 )))
428
429 (((
430 The user needs a USB-TTL adapter to connect the serial port to modify the node APPKEY.
431 )))
432
433 * (((
434 If a node is registered with multiple servers, it may also cause the "mic mismatch" error.
435
436
437
438
439 )))
440
441 = 10. Why i got the payload only with "0x00" or "AA~=~="? =
442
443
444 For US915, AU915 or AS923 frequencies.It is possible because: .
445
446 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.
447
448 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.
449
450 Solution: Use the decoder to filter out this 00 packet.
451
452 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]]
453
454
455
456 = 11. Why my Dev EUI and APP EUI is 0x000000000000, how to solve? =
457
458
459 (((
460 It is possible the keys is erased during upgrading of firmware. and the console output shows below after AT+CFG
461 )))
462
463 (((
464 AT+APPKEY=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
465 )))
466
467 (((
468 AT+NWKSKEY=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
469 )))
470
471 (((
472 AT+APPSKEY=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
473 )))
474
475 (((
476 AT+APPEUI=00 00 00 00 00 00 00 00
477 )))
478
479 (((
480
481 )))
482
483 (((
484 You can get the keys from the box sticker or send mail to Dragino Support to check keys with the provided SN number.
485 )))
486
487 (((
488 You can rewrites the keys by running commands in AT Console
489
490
491 )))
492
493 (((
494 **For example：**
495 )))
496
497 (((
498 AT+APPKEY=85 41 47 20 45 58 28 14 16 82 A0 F0 80 0D DD EE
499 )))
500
501 (((
502 AT+NWKSKEY=AA CC B0 20 30 45 37 32 14 1E 14 93 E2 3B 20 11
503 )))
504
505 (((
506 AT+APPSKEY=11 23 02 20 30 20 30 60 80 20 20 30 30 20 10 10
507 )))
508
509 (((
510 AT+APPEUI=2C 45 47 E3 24 12 23 24
511 )))
512
513 (((
514 (Any combination of 16 bit codes can be used）
515
516
517
518 = 12. I set my device is LoRaWAN Class C mode, why i still see Class A after boot? =
519 )))
520
521
522 Class C only refers to status after OTAA Join successfully. The OTAA Join Process will use Class A mode.
523
524
525
526 (% class="wikigeneratedid" %)
527