Hello,
I have a set of devices all of them with the module MC90. I am using them for localization purposes. The modules are using the EPO provisioning and Quectel reference location functionalities as it is said in the application note “MC60&MC90_GNSS_AGPS_Application_Note_V1.2”.
AT+QIFGCNT=2 //Set PDP context
OK
AT+QICSGP=1,“CMNET”//Configure APN
OK
AT+CREG?;+CGREG? //Check network status
+CREG: 0,2
+CGREG: 0,2
OK
AT+CREG?;+CGREG? //Check network status
+CREG: 0,1
+CGREG: 0,1
OK
AT+QGNSSTS? //Read time synchronization status
+QGNSSTS: 1 //Time synchronization completed
OK
AT+QGREFLOC=31.844376,117.204536 // Set reference location information for QuecFastFix Online
OK
AT+QGNSSEPO=1 //Enable EPOTM function
OK
AT+QGNSSC=1 //Power ON GNSS
OK
AT+QGNSSRD?
+QGNSSRD: $GNRMC,125349.093,V,0.00,0.00,010716,N50
$GNVTG,0.00,T,M,0.00,N,0.00,K,N2C
$GNGGA,125349.093,0,0,M,M,54
$GPGSA,A,1,1E
$GLGSA,A,1,02
$GPGSV,1,1,02,09,29,06,2974
$GLGSV,1,1,0065
$GNGLL,125349.093,V,N66
OK
AT+QGNSSRD?
+QGNSSRD: $GNRMC,125350.093,V,0.00,0.00,010716,N58
$GNVTG,0.00,T,M,0.00,N,0.00,K,N2C
$GNGGA,125350.093,0,0,M,M,*5C
$GPGSA,A,1,*1E
Until last saturday, 9 July 2022, all the modules have a Time to First Fix between ~10-30 seconds. Right now there are some modules that continue working as expected, but some modules have increased their Time to First Fix to ~5-10 minutes. All the tests has been done in open sky conditions and with 2G coverage.
It seams that the command “AT+QGREFLOC=31.844376,117.204536” is not taking effect. I have cheked that the introduced coordinates are correct. Could you explain me what are doing the modules once the reference coordinates are introduced? Why in some modules is woking and other modules stop working together.
I hope you can give me some support with the problem.
Thank you in advance.
Best regards,
Ferran