Hello! I am using the MC7455 dual SIM modem with two SIM cards and I am curious if it is possible to configure the modem to automatically switch between the two SIM cards based on some criterion (e.g., the signal level).
Also, in the case of manual switching, is it required to reset the modem after switching the SIM (AT!UIMS=0/1 followed by AT!RESET) or can it be done without reset?
Thank you,
Cristian M.
Hi cristi_m90,
Welcome you to our community.
No, it is.
It can be done without reset.
I have tried to switch between the SIM cards using AT!UIMS=0 and AT!UIMS=1, but it does not switch without reset (using either AT!RESET or mmcli --reset).
I confirm that AT!UIMS? shows the correct SIM in use, but mmcli does not change the information shown without resetting the modem.
E.g., this is the output of mmcli -m 0 when the modem is configured to use the first SIM (AT!UIMS=0):
mmcli -m 0
--------------------------------
General | dbus path: /org/freedesktop/ModemManager1/Modem/0
| device id: 423ee1a751dd729176268988b62195e119765b80
--------------------------------
Hardware | manufacturer: Sierra Wireless, Incorporated
| model: MC7455
| firmware revision: SWI9X30C_02.20.03.00 r6691 CARMD-EV-FRMWR2 2016/06/30 10:54:05
| carrier config: default
| h/w revision: 1.0
| supported: gsm-umts, lte
| current: gsm-umts, lte
| equipment id: 359072068612080
--------------------------------
System | device: /sys/devices/soc0/soc/2100000.aips-bus/2184200.usb/ci_hdrc.0/usb1/1-1
| drivers: qcserial, qmi_wwan
| plugin: Sierra
| primary port: cdc-wdm0
| ports: cdc-wdm0 (qmi), wwan1 (net), ttyUSB2 (at), wwan0 (net),
| cdc-wdm1 (qmi), ttyUSB1 (gps), ttyUSB0 (qcdm)
--------------------------------
Status | lock: sim-pin2
| unlock retries: sim-pin (3), sim-puk (10), sim-pin2 (3), sim-puk2 (10)
| state: connected
| power state: on
| access tech: lte
| signal quality: 81% (recent)
--------------------------------
Modes | supported: allowed: 3g; preferred: none
| allowed: 4g; preferred: none
| allowed: 3g, 4g; preferred: 3g
| allowed: 3g, 4g; preferred: 4g
| current: allowed: 3g, 4g; preferred: 4g
--------------------------------
Bands | supported: utran-1, utran-3, utran-4, utran-5, utran-8, utran-2,
| eutran-1, eutran-2, eutran-3, eutran-4, eutran-5, eutran-7, eutran-8,
| eutran-12, eutran-13, eutran-20, eutran-25, eutran-26, eutran-29,
| eutran-30, eutran-41
| current: utran-1, utran-3, utran-4, utran-5, utran-8, utran-2,
| eutran-1, eutran-2, eutran-3, eutran-4, eutran-5, eutran-7, eutran-8,
| eutran-12, eutran-13, eutran-20, eutran-25, eutran-26, eutran-29,
| eutran-30, eutran-41
--------------------------------
IP | supported: ipv4, ipv6, ipv4v6
--------------------------------
3GPP | imei: 359072068612080
| operator id: 22601
| operator name: Vodafone RO
| registration: home
--------------------------------
3GPP EPS | ue mode of operation: csps-2
--------------------------------
SIM | dbus path: /org/freedesktop/ModemManager1/SIM/0
--------------------------------
Bearer | dbus path: /org/freedesktop/ModemManager1/Bearer/8
| /org/freedesktop/ModemManager1/Bearer/0
This output does not change after changing to the second SIM (AT!UIMS=1). It changes only after modem restart.
Am I missing something?
Hi cristi_m90,
You need to enable SIM hot-swap feature
AT!ENTERCND=“A710”
AT!CUSTOM=“SIMHOTSWAPDIS”,0
AT!RESET
@Donald Hi. I have enabled it as you suggested, but the behavior is the same. Maybe the problem is related with the ModemManager.
Hi cristi_m90,
The SWI9X30C_02.20.03.00 is old firmware. Please update the latest MC7455 firmware to the module and retry.
You can get it here AirPrime EM/MC74xx Approved FW Packages