USB to secondary CF3



I have a wp module in both the primary (J200) and secondary CF (J601) slots. The secondary is connected to the primary through USB. I think dmesg shows the secondary registering:

[ 1.321379] usbserial: USB Serial support registered for GSM modem (1-port)
[ 1.321471] usbcore: registered new interface driver qcserial
[ 1.321562] usbserial: USB Serial support registered for Qualcomm USB modem
[ 1.321654] usbcore: registered new interface driver sierra
[ 1.321745] usbserial: USB Serial support registered for Sierra USB modem

But how can I talk to it ? Can I log into the module as root to configure it, use the cm tool through the command line etc ?

Secondly, I have changed the resistor configuration of R820 and R833 to route the secondary sim to the secondary module. Also on SW401 I’ve changed switch 5, SW_PWR_ON to enable POWER_ON signal to secondary module and switch 8, DCDC_shutdown to on ( it doesn’t make sense according to the mangOH greep DV4 User guide Rev. 3 but the led’s 3, 9 and 10 light up briefly like this, otherwise they dont light up at all).

But I have have no way of knowing whether the secondary module is working, much less how to control it even via the primary. Isn’t it possible to open a terminal to it, it doesn’t seem to get it’s own usb-ethernet address ? How to configure and connect the secondary cf3 via the first ?

Update: ok, so I detect it as a usb device, dmesg says its a Sierra modem and it gets a tty port, but how then to configure it, eg set the apn or change network options, get it to connect, read the signal strength etc ?

Can the usb port that enumerates be used to send AT commands to the secondary module ?


I can see three usb devices (/dev/ttyUSB1 to /dev/ttyUSB3) on the primary that correspond to the secondary cf3 acting as a sierra modem, and I can send AT commands and start a data connection, etc.

But I can’t for example ping out from the primary even I know the secondary has an IP address. There was a usb1 interface that ip addr identified, I’ve ipconfig’ed it to act as an interface and edited iptables to allow traffic, but I’m not even sure that the interface is the modem. I also haven’t been able to work out if i can ssh into the secondary ( though if it’s just going to act as a pass through that’s not a problem, but at least I should be able to ping out from the primary via the secondary).


For anyone’s information, this question has been pretty much answered by lotam on the legato forum here