# SIMCom A7680C LANS connection error

**URL:** <https://community.hivemq.com/t/simcom-a7680c-lans-connection-error/3932>\
**Category:** HiveMQ Cloud\
**Created:** [October 3, 2025, 8:21am UTC](https://community.hivemq.com/t/simcom-a7680c-lans-connection-error/3932 "2025-10-03T08:21:56Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![TOANPHAM](https://avatars.discourse-cdn.com/v4/letter/t/a87d85/32.png) [@TOANPHAM](https://community.hivemq.com/u/TOANPHAM)\
**Post date:** [October 3, 2025, 8:21am UTC](https://community.hivemq.com/t/simcom-a7680c-lans-connection-error/3932/1 "2025-10-03T08:21:56Z")

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**Dear Support Team,**

I am experiencing difficulties connecting my SIMCom A7680C LANS module to HiveMQ Cloud over TLS. I have reviewed the relevant documentation, uploaded the recommended CA certificate to the module, and enabled the required settings. The module appears to operate normally; however, every connection attempt results in an error.

Could you please advise on possible causes and recommended troubleshooting steps?

**Environment & steps taken**

- Device: SIMCom A7680C LANS

- Target: HiveMQ Cloud (TLS)

- Actions performed: loaded CA certificate, configured SSL/TLS (SNI and time checks as applicable), verified network registration and IP, started MQTT client, then attempted `ssl://` connect

- Current result: connection fails with an error message

I would appreciate your guidance. I can provide detailed logs (ATI/AT+GMR, `AT+CMEE=2` output, `AT+CSSLCFG?`, `AT+CMQTTSTART/CONNECT` traces) if helpful.

Thank you for your support.

 ![CONNECT](https://canada1.discourse-cdn.com/flex035/uploads/hivemq1/original/2X/7/7df2c7288471f3d69355c15e31a18aa589a82ca0.png)

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**Author:** ![hivemq-support](https://yyz1.discourse-cdn.com/flex035/user_avatar/community.hivemq.com/hivemq-support/32/357_2.png) [@hivemq-support](https://community.hivemq.com/u/hivemq-support)\
**Post date:** [October 6, 2025, 5:33pm UTC](https://community.hivemq.com/t/simcom-a7680c-lans-connection-error/3932/2 "2025-10-06T17:33:16Z")

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Hello​,

Could you try installing the attached CA certificate to the module and see if it helps?

Regards,  
Gil

(Attachment isrgrootx1.pem is missing)

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<div class="post-metadata">

**Author:** ![hivemq-support](https://yyz1.discourse-cdn.com/flex035/user_avatar/community.hivemq.com/hivemq-support/32/357_2.png) [@hivemq-support](https://community.hivemq.com/u/hivemq-support)\
**Post date:** [October 17, 2025, 1:18pm UTC](https://community.hivemq.com/t/simcom-a7680c-lans-connection-error/3932/3 "2025-10-17T13:18:47Z")

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Hello,

To assist further, could you please let us know your feedback on the issue? We look forward to hearing from you.  
​  
Regards,  
Gil