I installed Sierra Wireless R12 on my WP7607 device. (based upon Legato 18.10.3 and Linux Yocto 3.18.122)
I didn’t install any additional apps.
I use the command line tool ‘cm’ to configure my sim and apn settings, and I can create a mobile data connection to our APN network. ‘cm radio’ shows that the target is registered to the home network, and shows an excellent signal quality.
I execute a ping towards our server on the APN network, and I receive feedback as expected.
Then, I perform the following test:
I disconnect the MAIN antenna from the target board, to simulate signal/network problems.
‘cm radio’ shows that the signal quality drops to 0, and the target can’t register to the network anymore.
‘ping’ replies: “Network is unreachable”
To my opinion, this is expected behaviour.
But then, after a few seconds, the Legato system goes down and the SSH connection between host PC and target board is lost.
I can only create a new SSH connection after I disconnect/connect the supply of the target board.
I performed this test for more than 20 times, and each time the Legato system goes down when I disconnect the antenna.
The syslog does not indicate detailed info concerning this issue, so, I don’t have a clue how this can be fixed.
*swi-mdm9x28-wp user.info swiapp: qmi_at_unsol_ind_cb: ind id:33 *
swi-mdm9x28-wp user.info swiapp: Received AT command forward request from modem
swi-mdm9x28-wp user.info swiapp: fwdcmd.opcode=1
swi-mdm9x28-wp user.info swiapp: fwdcmd.name=$QCPWRDN
swi-mdm9x28-wp user.info swiapp: fwdcmd.ntokens=0
swi-mdm9x28-wp user.info swiapp: ctrCond signalling complete.
swi-mdm9x28-wp user.info swiapp: Recieved ctrCond: p: 0, S:0, nr: 1
swi-mdm9x28-wp user.info swiapp: QCPWRDN has been detected
swi-mdm9x28-wp user.warn kernel: [ 218.938891] PSM: Modem oprt mode - 3