Hello there 
I’m having trouble in using MQTT in my module…
I copy and paste here my log (it’s a trace of the serial communication, the “>” and “<” are not part of it and mean, respectively, “>towards the EC21 module”, “<from the EC21 module”).
ATI
<ATI
Quectel
EC21
Revision: EC21EFAR02A06M4G
OK
AT+GMR
<AT+GMR
EC21EFAR02A06M4G
OK
AT+CMEE=2
<AT+CMEE=2
OK
AT+QCFG=“nwscanseq”,020301
<AT+QCFG=“nwscanseq”,020301
OK
AT+CFUN=1,0
<AT+CFUN=1,0
OK
AT+CTZU=1
<AT+CTZU=1
OK
AT+GSN
<AT+GSN
861108031118788
OK
AT+CIMI
<AT+CIMI
234301951052818
OK
AT+COPS=0
<AT+COPS=0
OK
AT+CGREG?
<AT+CGREG?
+CGREG: 0,5
OK
AT+CSQ
<AT+CSQ
+CSQ: 15,99
OK
AT+QNWINFO
<AT+QNWINFO
+QNWINFO: “FDD LTE”,“22201”,“LTE BAND 20”,6300
OK
AT+QSSLCFG=“seclevel”,0,2
<AT+QSSLCFG=“seclevel”,0,2
OK
AT+CGATT?
<AT+CGATT?
+CGATT: 1
OK
AT+QICSGP=1,1,** omitted, but is a valid value **
<AT+QICSGP=1,1,** omitted, but is a valid value **
OK
AT+QICSGP=1
<AT+QICSGP=1
+QICSGP: 1,** omitted, but is a valid value **
OK
AT+QFDEL=“RAM:"
<AT+QFDEL="RAM:”
OK
AT+QFUPL=“RAM:cert.pem”,1672
<AT+QFUPL=“RAM:cert.pem”,1672
CONNECT
-----BEGIN CERTIFICATE-----
******** omitted ********
-----END CERTIFICATE-----
<AQFUPL: 1672,7401
OK
AT+QFUPL=“RAM:root.pem”,1219
<AT+QFUPL=“RAM:root.pem”,1219
CONNECT
-----BEGIN CERTIFICATE-----
******** omitted ********
-----END CERTIFICATE-----
<AQFUPL: 1219,141d
OK
AT+QFUPL=“RAM:key.pem”,1678
<AT+QFUPL=“RAM:key.pem”,1678
CONNECT
-----BEGIN RSA PRIVATE KEY-----
******** omitted ********
-----END RSA PRIVATE KEY-----
<AQFUPL: 1678,3a3b
OK
Then if I send any kind of “QMTCFG” command, I always get an error.
Like, for example
AT+QMTCFG=“version”
<AT+QMTCFG=“version”
ERROR
What I’m missing? I was perfectly able to call those commands with a BG96.
Thank you in advence!
