Wiki source code of Signal Strength:99. CSQ:99,99
Last modified by Xiaoling on 2023/04/24 08:49
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10.1 | 1 | **Table of Contents:** |
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7.1 | 6 | = 1. Issue Output = |
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5.2 | 7 | |
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5.3 | 8 | ---- |
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7.1 | 10 | NB-IoT module can't connect to NB-IoT Network and Keep Showing Signal Strenght:99. Below is an example output: |
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1.3 | 11 | |
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7.1 | 12 | [[image:image-20230423223628-1.png]] |
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| 15 | = 2. What is Signal Strenght? = | ||
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10.3 | 17 | |
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10.2 | 18 | Signal Strength is same as AT+CSQ command output. When you run (% style="color:blue" %)**AT+CSQ**(%%) and NB-IoT module return (% style="color:blue" %)**AT+CSQ=99,99**(%%). It means NB-IoT Sensor doesn't attached to the NB-IoT network. If attached to network, the first 99 should be 2~~31. |
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7.1 | 19 | |
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1.4 | 20 | ((( |
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5.2 | 21 | Below is the definition for the (% style="color:blue" %)**AT+CSQ** |
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1.4 | 22 | ))) |
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1.3 | 23 | |
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4.1 | 24 | [[image:image-20220530094441-1.png]] |
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1.3 | 25 | |
| 26 | CSQ Definition | ||
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4.1 | 28 | |
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7.1 | 29 | = 3. What to check? = |
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5.1 | 30 | |
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9.1 | 31 | == 3.1 Check whether module detect the SIM card? == |
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1.3 | 32 | |
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10.3 | 33 | |
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10.2 | 34 | You can see if the output shows the (% style="color:blue" %)**IMSI number**(%%). If NB-IoT module detects SIM card successful, There will be a IMSI number shown, this is from the SIM card. If SIM card not detect, please check: |
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7.1 | 35 | |
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9.1 | 36 | * If SIM card is placed in correct direction. |
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10.2 | 37 | |
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9.1 | 38 | * Make sure there is power off / power on after insert SIM card. |
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5.4 | 39 | |
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10.3 | 40 | |
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9.1 | 42 | == 3.2 Whether you use a NB-IoT SIM card that the module supports == |
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5.4 | 43 | |
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10.2 | 44 | * Make sure the SIM card you use is a (% style="color:blue" %)**NB-IoT SIM card**(%%). It is different from normal SIM card we use for mobile. |
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5.4 | 45 | |
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10.2 | 46 | * If you use a NB-IoT SIM card, check whether the (% style="color:blue" %)**Frequency Band**(%%) of this operator are in the support list of the NB-IoT Sensor. |
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10.3 | 48 | |
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9.1 | 50 | == 3.3 Whether the antenna connection is good == |
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10.3 | 53 | See the connection of Antenna Path is loose. |
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9.1 | 56 | [[image:image-20230423230549-2.png||height="370" width="428"]] |
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| 59 | == 3.4 Check Software Settings == | ||
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10.3 | 61 | |
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9.1 | 62 | In the NB-IoT Sensor which power by battery. The sensor will try to connect to NB-IoT in a specify time (For example 5 minutes), if sensor is not able to attach network in 5 minutes. Sensor will stop retry and put the NB-IoT module in sleep mode to save battery life. So in the case that attaching network needs more time than 5 minutes, it will cause module hard to attach NB-IoT network. There are two solution to solve this. |
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10.3 | 64 | |
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9.1 | 65 | === 3.4.1 Extend attach time === |
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10.3 | 67 | |
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10.2 | 68 | User can use AT Command to extend network acquisition time.For example (% style="color:blue" %)**AT+CSQTIME=10**(%%) will extend the network acquisition time to 10 minutes. |
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9.1 | 69 | |
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| 71 | === 3.4.2 Lock Frequency Band === | ||
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10.3 | 73 | |
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9.1 | 74 | NB-IoT module by default support multi-bands, and it will try to use these bands to attached network one by one. User can lock the frequency band to the SIM card band to speed up the process. |
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| 76 | See [[how to lock frequency band>>doc:Main.Specify NB-IoT Band.WebHome]]. | ||
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5.2 | 78 |