[Evaluation of EC-01F-Kit, the NB-IoT development board of Essence] 03. Discussion: Frequent disconnection after the device is connected to the network

李百仪

[Evaluation of EC-01F-Kit, the NB-IoT development board of Essence] 03. Discussion: Frequent disconnection after the device is connected to the network [Copy link]

When debugging EC-01F MQTT to access Alibaba, the normal communication state is frequently disconnected and then automatically connected to the network. The antenna has been replaced with a 4G suction cup high-gain antenna. What is the reason?

The following is the debug log:

[2021-12-19 14:36:18.344 R]

+CREG: 6 // Registered to the "SMS only" network ( only applicable when <AcT> is E -UTRAN )

+CEREG: 1 //1 has been registered to the local network

[2021-12-19 14:36:41.108 R]

+CREG: 0 //0 No network is registered, MT does not search for new network

+CEREG: 0 //0 No network registered, MT does not search for new network

+CEREG: 2 //2 No network registered, MT is searching for a new network

[2021-12-19 14:36:50.442 R]

+CREG: 6 //6 has been registered to the "SMS only" network ( only applicable when <AcT> is E -UTRAN )

+CEREG: 1 // Registered to the local network

[2021-12-19 14:36:52.837 R]

+ECMTSTAT: 0,1 //+ECMTSTAT URC message, reporting link layer status <err_code> integer. Error code err_code: 1 The connection has been closed or reset by the peer

[2021-12-19 14:37:04.988 R]

+ECMTCONN: 0,0,0 //+ECMTCONN:<tcpconnectID>,<result>[,<ret_code>]result:0 Data was sent successfully and a reply from the server was receivedret_code:0 Connection to the server was successful

[2021-12-19 14:37:40.695 R]

+ECMTSTAT: 0,1 //+ECMTSTAT URC message, reporting link layer status <err_code> integer. Error code err_code: 1 The connection has been closed or reset by the peer

[2021-12-19 14:37:51.604 R]

+ECMTCONN: 0,0,0 //+ECMTCONN:<tcpconnectID>,<result>[,<ret_code>]result:0 Data was sent successfully and a reply from the server was receivedret_code:0 Connection to the server was successful

[2021-12-1916:18:38.377T]AT+ECMTPUB=0,0,0,0,"/sys/a1KApkvNNDZ/EVN_2021_4_17/thing/event/property/post",{"params：{"temperature":33.8,"CO2":10.27},"method":"thing.event.property.post","id":1}

[2021-12-19 16:18:38.493 R]

OK

+ECMTPUB: 0,0,0

[2021-12-19 16:18:40.093 R]

+ECMTRECV: 0,0,"/sys/a1KApkvNNDZ/EVN_2021_4_17/thing/event/property/post_reply",{"code":200,"data":{},"id":"1","message":"success","method":"thing.event.property.post","version":"1.0"}

[2021-12-19 16:22:08.695 R]

+ECMTSTAT: 0,1 //+ECMTSTAT URC message, reporting link layer status <err_code> integer. Error code err_code: 1 The connection has been closed or reset by the peer

[2021-12-19 16:22:15.955 R]

+CREG: 0 //0 No network is registered, MT does not search for new network

+CEREG: 0 //0 No network registered, MT does not search for new network

+CERE G: 2 // No network registered, MT is searching for a new network

[2021-12-19 16:22:27.791 R]

+CREG: 6 // Registered to the "SMS only" network ( only applicable when <AcT> is E -UTRAN )

+CEREG: 1 //1 has been registered to the local network

[2021-12-19 16:22:30.960 R]

+ECMTCONN: 0,0,0 //+ECMTCONN:<tcpconnectID>,<result>[,<ret_code>]result:0 Data was sent successfully and a reply from the server was receivedret_code:0 Connection to the server was successful

[2021-12-19 16:33:09.244 R]

+ECMTSTAT: 0,1 //+ECMTSTAT URC message, reporting link layer status <err_code> integer. Error code err_code: 1 The connection has been closed or reset by the peer

[2021-12-19 16:33:21.712 R]

+ECMTCONN: 0,0,0 //+ECMTCONN:<tcpconnectID>,<result>[,<ret_code>]result:0 Data was sent successfully and a reply from the server was receivedret_code:0 Connection to the server was successful

lugl4313820

Are there too many requests? I use MQTT to connect to my network, and it is very stable! It has not been disconnected for half a day!

李百仪

lugl4313820 posted on 2021-12-19 21:08 Are there too many requests? I use MQTT to connect to my network, which is very stable! It has not been disconnected for half a day!

PC tested it through AT command, but it didn't work after connecting, and it dropped out every once in a while

annysky2012

Is it because the PC does not send heartbeats at a fixed time?

李百仪

annysky2012 posted on 2021-12-20 08:48 Is it because the PC does not send heartbeats at a fixed time?

This application does not use the MCU to maintain the heartbeat.

1.EC-01F supports MQTT protocol. MCU only needs to operate MQTT configuration of EC-01F: Configure keepalive time->AT+ECMTCFG="keepalive",0,30\r

2. If the MCU builds the MQTT protocol through TCP, it needs to maintain the keep-alive time itself.

lugl4313820

Li Baiyi posted on 2021-12-20 08:37 The PC was tested through AT commands, but it didn't work when connected, and it dropped the line every once in a while

20 Configuring the keep-alive time

AT+ECMTCFG="keepalive",0,30\r

Please try this parameter more.

lugl4313820

In addition, the MQTT server also has regulations. If you send illegal data or send it too frequently, it will actively kick you offline.

李百仪

lugl4313820 posted on 2021-12-20 12:52 In addition, the MQTT server also has regulations. If you send illegal data or send it too frequently, it will actively kick you offline.

1. Search in Alibaba Cloud Help Documents:

How to set the heartbeat interval?

In IOT_MQTT_Construct, you can set the value of keepalive_interval_ms, which is used by the IoT platform as the heartbeat interval. The value range of keepalive_interval_ms is 60000~300000.

2. The Alibaba Cloud MQTT protocol specification does not mention this limitation https://help.aliyun.com/document_detail/30540.html . I will try to configure it to 60+.

3. PC sends debugging instructions to eliminate the possibility of illegal data.

4. Does not registering to the network have anything to do with this problem?

李百仪

It should be ok to change the MQTT keepalive time configuration.

博安通

Is the paddle antenna not effective? Why switch to a 4G suction cup antenna?

李百仪

Bo Antong published on 2022-1-20 14:47 Is the paddle antenna not effective? Why change to a 4G suction cup antenna?

The paddle antenna doesn't work well indoors. I tried several antennas and got the same problem.

https://item.taobao.com/item.htm?spm=a1z09.2.0.0.1e142e8dKBDK6H&id=592809751730&_u=kmm6pvk7e2b

The selected one is 2G/GSM/NB/6dBi/309mm. Feeder length: 2m