I am unable to get a signal using AT+CSQ
It was working fine until a couple of days ago but now it almost always returns
+CSQ: 99,99
I am not sure if something has inadvertently been reset.
Very occasionally it does get a signal and I can move on to AT+CEREG but this only ever returns +CEREG: 0,2 or +CEREG:0,3 and never returns +CEREG: 0,5
Any assistance would be much appreciated.
how about using AT+CESQ?
Here are the responses I get …
AT+CESQ?
+CME ERROR: 3
AT+CESQ
+CESQ: 99,99,255,255,255,255
then it seems not receiving any signal
What could be the cause of this ? There is definitely a signal available here.
did you connect antenna?
Yes it is connected to an antenna. This was working ok 2 days ago - I am trying to establish what has changed and whether something in the modem has been reset but I don’t know what I am looking for.
Have you changed another sim card?
I have tried with 2 different sim cards - same problem
Have you tried another module?
I only have the one development board so cannot try another
Can it read the sim card?
Yes it can, I can issue AT+CCID and it returns the sim card number 
AT+CCID
+CCID: 89462038075006833002
Are there other commands I should try ?
Did you check at+ksrat? And at+cgdcont?
BTW, which FW are you using right now?
Is it 4.6.9.4?
AT+KSRAT=1,1 solved the CSQ problem but I still have issues later down the sequence.
I am now getting and CME ERROR 921 after the AT+KCNXUP command which I have not had before.
My full sequence is as follows
AT
OK
AT+CSQ
+CSQ: 7,99
OK
AT+CEREG?
+CEREG: 0,5
OK
AT+KCNXCFG=1,“GPRS”,“dataconnect.m2m”
OK
AT+CGATT=1
OK
AT+KCNXUP=1
+CME ERROR: 921
As for firmware, does this give you the information ?
ati9
HL7810.5.5.14.0-23.12.0.FreeRTOS.w49
HL78xx.5.5.14.0.RK_03_02_00_00_40522_001.20240207
2024/02/07 15:48:28
IMEI-SV: 3547205103528717
Legato RTOS: 23.12.0.FreeRTOS.w49 2023/11/15 07:10:33
atSwi: HL78XX.5.5.13.0-23.12.0.FreeRTOS.w49
UBOOT: 01.03
Apps: RKAPP_03_02_00_00_40241_008__6f2182ee7bf4ecb5de5081714f10fdc863a2d28a
MAC: ALT1250_03_02_00_00_40521_NB
PHY: 0.0.323194
PMP: 323669
AISE: ISE2APP_00_00_00_09
SBUB: 1
SBFW: 1
FPuK1: 1B993663
FPuK2: 25DF28C5
RBUB: 0
RBFW: 0
MCU-Disable: 1
I just tried using id 2 for the connection as follows
AT+KCNXCFG=2,“GPRS”,“dataconnect.m2m”
OK
AT+KCNXUP=2
OK
+KCNX_IND: 2,4,1
+KCNX_IND: 2,1,0
AT+KCNXCFG?
+KCNXCFG: 1,“GPRS”,“dataconnect.m2m”,“”,“”,“IPV4”,“0.0.0.0”,“0.0.0.0”,“0.0.0.0”,0
+KCNXCFG:2,“GPRS”,“dataconnect.m2m”,“”,“”,“IPV4”,“10.168.78.160”,“130.244.127.161”,“130.244.127.169”,2
Why would ID 2 work but ID 1 fail ?
Not sure if the cid 1 is used for other purpose such as AVMS
I have been using ID1 for weeks - it’s only just stopped working
Did you change any setting? (just like +KSRAT is changed before)
KSRAT is the only change I have made