my test shows that the “SR” value will not go up after sending SMS
at+cnmi=1,2,0,1,0
OK
ati3
Manufacturer: Sierra Wireless, Incorporated
Model: MC7455
Revision: SWI9X30C_02.38.00.00 rE3F3E55C03AE94 jenkins 2022/01/13 05:16:00
MEID: 35907206012345
ESN: 12800012345, 80012345
IMEI: 359072060012345
IMEI SV: 22
FSN: LQ530100512345
+GCAP: +CGSM
OK
at+cpms="SR"
+CPMS: 0,30,0,40,0,40
OK
at+cmgs="1234567"
> asdfqwer
+CMGS: 10
OK
at+cpms?
+CPMS: "SR",0,30,"SM",0,40,"SM",0,40
OK