# Operating modes

**URL:** <https://forum.sierrawireless.com/t/operating-modes/28029>\
**Category:** RC76\
**Created:** [October 5, 2022, 10:00am UTC](https://forum.sierrawireless.com/t/operating-modes/28029 "2022-10-05T10:00:50Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![saim](https://avatars.discourse-cdn.com/v4/letter/s/c57346/32.png) [@saim](https://forum.sierrawireless.com/u/saim)\
**Post date:** [October 5, 2022, 10:00am UTC](https://forum.sierrawireless.com/t/operating-modes/28029/1 "2022-10-05T10:00:50Z")

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Hi,

I am using AT+CFUN to set the operating mode for my LTE modem. I have RC7620.  
The modem seems to allow following modes

// Minimum Functionality  
AT+CFUN=0

// Full Functionality  
AT+CFUN=1

// Low-power  
AT+CFUN=4

// Factory test  
AT+CFUN=5

// Reset  
AT+CFUN=6

// Offline  
AT+CFUN=7

What is the difference between AT+CFUN=0 and AT+CFUN=4?  
Both modes seem to behave like ‘low-power’ mode.

Thanks  
Sai

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**Author:** ![jerdung](https://avatars.discourse-cdn.com/v4/letter/j/82dd89/32.png) [@jerdung](https://forum.sierrawireless.com/u/jerdung)\
**Post date:** [October 10, 2022, 10:24am UTC](https://forum.sierrawireless.com/t/operating-modes/28029/2 "2022-10-10T10:24:25Z")

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Hi @saim ,  
According to the AT Command Reference Guide, the RC7620 only supports cfun=0 (minimum functionality) and cfun=1 (full functionality)  
For more details, please refer to Section 18 - Supported GSM/WCDMA AT Commands on page 8 in the link below:  
[https://source.sierrawireless.com/resources/airprime/software/airprime---rc76xx---at-command-reference-guide/#sthash.QlRvcKOr.dpbs](https://source.sierrawireless.com/resources/airprime/software/airprime---rc76xx---at-command-reference-guide/#sthash.QlRvcKOr.dpbs)

Thanks,

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<div class="post-metadata">

**Author:** ![saim](https://avatars.discourse-cdn.com/v4/letter/s/c57346/32.png) [@saim](https://forum.sierrawireless.com/u/saim)\
**Post date:** [October 10, 2022, 10:50am UTC](https://forum.sierrawireless.com/t/operating-modes/28029/3 "2022-10-10T10:50:54Z")

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Yes I saw that, but the modem seems to respond to more values than what is mentioned in the AT command manual.

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**Author:** ![jerdung](https://avatars.discourse-cdn.com/v4/letter/j/82dd89/32.png) [@jerdung](https://forum.sierrawireless.com/u/jerdung)\
**Post date:** [October 12, 2022, 9:23am UTC](https://forum.sierrawireless.com/t/operating-modes/28029/4 "2022-10-12T09:23:50Z")

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Hi @saim ,  
Basically, Sierra highly recommends customer use AT commands which are described in AT command document. In case, you would like to use some un-documennted commands, please contact technical support via email to [support@sierrawireless.com](mailto:support@sierrawireless.com) for further support.

Thanks,