# Application suddenly does not work sometimes

**URL:** <https://forum.sierrawireless.com/t/application-suddenly-does-not-work-sometimes/7498>\
**Category:** General wireless topics\
**Created:** [October 14, 2014, 7:22am UTC](https://forum.sierrawireless.com/t/application-suddenly-does-not-work-sometimes/7498 "2014-10-14T07:22:35Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![sambk87](https://avatars.discourse-cdn.com/v4/letter/s/4491bb/32.png) [@sambk87](https://forum.sierrawireless.com/u/sambk87)\
**Post date:** [October 14, 2014, 7:22am UTC](https://forum.sierrawireless.com/t/application-suddenly-does-not-work-sometimes/7498/1 "2014-10-14T07:22:35Z")

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Hi all,  
Has anyone experienced that the application suddenly seems not to work although OpenAT operation still works. The phenomenon is as below:  
\_ No message is sent via UART anymore.  
\_ No response for an application-AT-command.  
\_ Normal response for an OpenAT-command such as: AT+WOPEN? returns 1  
\_ Ring normally for an incomming call.

If i restarts the application, it will work. If i let it be, it will work again after about some hours!!!

I am using SL6087, Firmware 7.51.  
I look forward to any suggestion from someone who experienced this error or knows which causes can potentially make this error?

Thanks in advance  
Pham Viet Sam

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**Author:** ![Rex\_alex](https://avatars.discourse-cdn.com/v4/letter/r/73ab20/32.png) [@Rex\_alex](https://forum.sierrawireless.com/u/Rex_alex)\
**Post date:** [October 15, 2014, 8:32am UTC](https://forum.sierrawireless.com/t/application-suddenly-does-not-work-sometimes/7498/2 "2014-10-15T08:32:09Z")

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hi,  
what exactly your applications is doing?  
Could you please provide your exact use case …

Regards,  
Rex

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**Author:** ![sambk87](https://avatars.discourse-cdn.com/v4/letter/s/4491bb/32.png) [@sambk87](https://forum.sierrawireless.com/u/sambk87)\
**Post date:** [October 15, 2014, 9:20am UTC](https://forum.sierrawireless.com/t/application-suddenly-does-not-work-sometimes/7498/3 "2014-10-15T09:20:16Z")

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> [@Rex\_alex](#):
>
> hi,  
> what exactly your applications is doing?  
> Could you please provide your exact use case …
> 
> Regards,  
> Rex

Hi Rex\_alex,  
My application periodically reads data from UART port then sends it to a remote server via GPRS. Besides, there are some application-AT-commands that i can type via monitor-USB-port.

Normally, my application works OK but recently, i have encountered that the application sometimes seems to stop or be suspended, i don’t know. The problem state is as above.