SIM7080G GSM modem module cannot detect the network

Ilya Filimonov 0
Viewed 45

I'm trying to figure out the SIM7080G module. The problem is related to the fact that I can not connect to a cellular operator. The SIM card I am using is working. Checked on a smartphone.

I met a similar situation on the forums (link, link), but there is no final solution anywhere. Next, I lay out a series of commands that I run to determine the states.

AT+CPIN?
+CPIN: READY
OK

AT+CSQ
+CSQ: 99.99
OK

AT+CGDCONT=1,"IP","Internet"
OK

AT+CNMP
+CNMP: 38
OK

AT+CGATT?
+CGATT: 0
OK

AT+CGNAPN?
+CGNAPN: 0,””
OK

AT+COPS?
+COPS: OK

AT+CNACT=1,1
+APP PDP: 0,DEACTIVE

AT+COPS=?
+COPS: ERROR

AT+CGATT=1
+CGATT: ERROR

I will say in advance that I can not display the error code. Described the problem here.

Could this be because the SIM card I'm using doesn't work with either NB-IoT or CAT-M? As I understand it, it should work with GSM and it suits me, but now nothing comes out.

I often saw advice to check the power that is supplied to the module. A little later, there will be an opportunity, I'll check.

Please tell me what could be the reason.

Thanks in advance.

at-command sim-card gsm
2 Answers

The problem is in the setting of

AT+CNMP
+CNMP: 38
OK

According to the AT command guide the response

+CNMP: <mode>

shows the selected type of network, where

<mode>
2 Automatic
13 GSM only
38 LTE only
51 GSM and LTE only

You should get the desired behavior by setting GSM mode:

AT+CNMP=13
Roberto Caboni0

The problem was solved. It consisted in the wrong organization of the power supply of the module. In response, I received a number of responses from the module (RDY, CFUN: 1, CPIN: READY, SMS Ready), which indicated that the module was restarted. The specification describes how to apply signals to the VBAT and PWKEY pins and hold the desired time. When I corrected the initialization, everything worked.

Also, the module does not really work in the GSM network and is intended exclusively for NB-IoT and CAT-M.

Ilya Filimonov0
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