# \[SL8084T\]\[OPAT\]LLH error when uart\_open

**URL:** <https://forum.sierrawireless.com/t/sl8084t-opat-llh-error-when-uart-open/6953>\
**Category:** Open AT\
**Created:** [January 8, 2014, 3:06am UTC](https://forum.sierrawireless.com/t/sl8084t-opat-llh-error-when-uart-open/6953 "2014-01-08T03:06:17Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![kagakuka](https://avatars.discourse-cdn.com/v4/letter/k/c68b51/32.png) [@kagakuka](https://forum.sierrawireless.com/u/kagakuka)\
**Post date:** [January 8, 2014, 3:06am UTC](https://forum.sierrawireless.com/t/sl8084t-opat-llh-error-when-uart-open/6953/1 "2014-01-08T03:06:17Z")

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[Application Type] Embedded Board  
[Platform]  
OPAT(2.52.0.201312091418)  
Developer Studio 2.3.2(Build ver: 2.3.2.201310241753)  
[Description]  
When I open UART1 port by the uart\_access sample application,  
LLH error was occurred then can’t get local echo.  
(Please see “bad trace”.)

Procedure is as follows.

1. Run OPAT Application by +WOPEN=1  
2.Send +WMFM=0,0,1 to close UART1  
3.Send +WDU=1,115200  
\*Never send the data from external host via UART.

2014/01/08;10:50:33:225;004;LLH;3;EVENT : ERROR 1c  
2014/01/08;10:50:33:235;001;LLH;3;EVENT : ERROR c  
2014/01/08;10:50:33:245;003;LLH;3;EVENT : ERROR 1c

I can’t find the meaning of these errors, sorry.

1.What do they mean?And, please tell us the reason why this error was occurred. 2.How to solve this error?

BTW, how can I know the meaning of LLH/HLH trace ?  
I’d like to know the way to search it.

Thank you.  
[Bad trace.txt](https://forum.sierrawireless.com/uploads/short-url/qdFlxnjYhH0wubVPRIX6WcpvNCk.txt) (745 Bytes)

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<div class="post-metadata">

**Author:** ![davidc](https://avatars.discourse-cdn.com/v4/letter/d/a183cd/32.png) [@davidc](https://forum.sierrawireless.com/u/davidc)\
**Post date:** [January 13, 2014, 11:04pm UTC](https://forum.sierrawireless.com/t/sl8084t-opat-llh-error-when-uart-open/6953/2 "2014-01-13T23:04:59Z")

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Hiya,

Just a thought - have you got the Interrupt stack set up in your application?

Have a look in ‘generated.c’ or search your project for something similar to

```auto
adl_InitIRQLowLevelStackSize
```

Also, can you please post your Low Level Interrupt code (remember to use the Code tags to get the format right!).

ciao, Dave

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**Author:** ![ado1](https://avatars.discourse-cdn.com/v4/letter/a/4af34b/32.png) [@ado1](https://forum.sierrawireless.com/u/ado1)\
**Post date:** [January 20, 2014, 8:40am UTC](https://forum.sierrawireless.com/t/sl8084t-opat-llh-error-when-uart-open/6953/3 "2014-01-20T08:40:28Z")

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Hiya,

If I’m right, the error means:

- parity error  
-framing error
- BREAK condition detected on the RXD pin

Certainly the uart is not correctly configured in your openat application: please try to review the open code.

thanks.