Recommendations for Autostart delay (EHS6 in particular) | Telit Cinterion IoT Developer Community
September 26, 2016 - 12:59pm, 2323 views
Hello,
I have read all documentation about Autostart, delay, JRC, sjam, ... and so fourth but I would like to know when it is worth setting a delay of a few seconds in the Autostart/Delay parameters, in particular for EHS6 modems.
Since years we have set (on previous models) delays of at least 25 seconds in order to let the modem initialize and read the SIM but is it still necessary with EHS6 modems ? [1]
Should we effectively consider that the Userware/Oracle-Autostart features are now judiciously initiated only once the modem is fully initialized and ready? (I mean enough to not encounter any internal issue or AT command freeze or lag?) [2]
This question comes after one of our modules running for days encountered a SIM network registration issue:
- after working for 2 days and following a reboot (triggered by our software), the modem couldn't register again (ever) to the cellular services. Our software and AT^SIND reported that the SIM was inserted but not ready/not registered to the cellular network.
- subsequent manual and automatic reboots of the modem didn't fix the issue
- a total power reset however fixed the issue (service was back)
We do not really understand what happened except that the Autostart/delay is set to 0. And I was used to think that it was not a good idea. Our software starts making AT calls and checking SIM states only a few seconds after starting. Could it impact the booting procedure of the modem...?
Thank you in advance for your shares,
Regards,
Bruno
Hello,
The "0" delay is the default value and usually it is not necessary to change it in the production version of application. Additionally there is any information in any documents about the necessary minimum or advised value.
During the development it can sometimes help when there are bugs in the application that make it crash.
But I would say that it depends on the customer scenario if it makes sense to delay the autostart.
There probably are some tasks that initiate in the background after the module boots. Everybody would like the shortest possible boot time so there surely are some actions that can be done in the background while the module is already operational.
But in case of EHS6 and other new modules some of the functionality is also implemented in the factory MIDlet (JRC) which is started with the same delay as the userware. And here comes the recommendation to set at least 2 for "Oracle-MIDlet-Autostart" just to make sure that the userware will not be started before JRC.
So if you would really want to add some delay for security maybe it would be the best to do it in the application.
On the other hand I don't really think that your issue had something to do with autostart delay. Maybe you should also verify how your application reboots the module - it is recommended to do it by AT command and not by hardware reset or cutting off the power. Another thing is hardware design - when the module is switched off there should not be any power on any pins of the module.
But at the moment it is hard to say what could have caused this malfunction.
If this was just one incident it might be really hard to find the source of it.
Best regards,
Bartłomiej
Hi,
thanks for the reply, it helped as well as the following topic which is directly link to our issue:
https://iot-developer.thalesgroup.com/threads/ehsx-disable-urc-asc01
We also had a design mismatch around the SIM card holder pins. This explained the loss of service after emergency resets of the modem (in addition to the perturbations observed at every reboot, potentially affecting the device on the other side of ASC0).
Greetings,
Bruno
Thank you for the summary.
Regards,
Bartłomiej