EM7565 - issues to be clarified -


#1

Hi All,
I cannot really understand why sometimes the SDK is

  • unable to find the 4G device ?.. (when trying to enumerate all the devices)
  • why sometimes some callback cannot be registered ?..
  • some other time, when it just finds the device it turn into a case where it says that no profile exist on device…

All this issues are really annoying because just before that I could use the modem to initiate a transfert (start the SDK -> IP up -> sending a file -> stop the SDK -> IP down) and on the next turn one of these issues happened, I wish to understand how I could make it a bit more robust?
Any tips/ideaS welcome :wink:
Thanks
Johann


#2

@johann,

Its a bit of a wide ranging question/request here, generically speaking the unit/SDK is pretty reliable and with most issues coming down to things like permissions on the system for the SDK execuatable and interfaces. Consequently you are going to need to be a bit more precise.

I presume you are using the Sierra drivers and SDK rather than the open source qmi_wwan/qcserial/qmilib ones?

Regards

Matt


#3

@matthew.dolan

Effectively I use the sierra SDK, while the [quote=“mlw, post:2, topic:14901”]qmi_wwan/qcserial/qmilib
[/quote]
works very well unfortunatelly I have no other choice than using the SDK provided by sierra.
To avoid any permissions issues I even tested it in root! and this does not change nothing.
I notice an issue related to USB. At the momet I use a USB interface to connect the modem. To get rid of the “Unable to find any 4G device” error message I have unplug/replug the USB module and then magic stuff happened the modem was detected again…
I do not have so much time to investigate but it is seriously a case of non robustness when the device will be embedded and in its own…
So If anyone as encountered any such a trouble, I will be please to get any tips or informations!
Best regards
Johann


#4

@johann,

All I can really suggest is to make sure that you see the /dev/qcqmi interface and that its permissions are set to allow you to access it before starting the QMI daemon. Note the QMI interface appears several seconds after the /dev/ttyUSB ones so don’t rely on checking these first (i.e. AT commands) as while the EM75 will be up and ready the system won’t.

Regards

Matt


#5

@mlw,
yes I got all the USB interfaces and I have the device about 4 seconds later, which is normal behaviour.
All the permissions are set correctly, that’s why I do not understand why those errors can arise?..
still searching…


#6

Here is another behaviour that I can observe from time to time but unfortunately I cannot track the cause.
the SDK has been launched and is in a CONNECTED state, the interface i UP with an IP, IPsec is established but no more transfert is possible and I got no error messages…
When I ‘reset’ the usb at the moment unplugging/plugging the modem module then everything goes back to normality.
If someone has an idea or tip(s) it could be great.
Thanks.
Johann


#7

@johann,

Why do you specifically it is something to do with the 74 or its QMI daemon? The issue could easily lie elsewhere.

Regards

Matt


#8

What others possibilities are left? when using nmcli everything works fine and such errors do not show up.
What else could it be?
I have to use the SDK and not the open-source implementation, so I have to find a way to make it works in a more robust fashion over time…


#9

@johann,

There are a lot of possibilities, you need to engage with the support of your commercial channel to get some more indepth help than I can provide here.

Regards

Matt