# Unable to publish or Subscribe rostopics using mavlink with gazebo and px4..getting errors

**URL:** <https://discuss.px4.io/t/unable-to-publish-or-subscribe-rostopics-using-mavlink-with-gazebo-and-px4-getting-errors/3166>\
**Category:** Uncategorized\
**Created:** [April 30, 2017, 2:14am UTC](https://discuss.px4.io/t/unable-to-publish-or-subscribe-rostopics-using-mavlink-with-gazebo-and-px4-getting-errors/3166 "2017-04-30T02:14:50Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Neelesh](https://discuss.px4.io/letter_avatar_proxy/v4/letter/n/9de0a6/32.png) [@Neelesh](https://discuss.px4.io/u/Neelesh)\
**Post date:** [April 30, 2017, 2:14am UTC](https://discuss.px4.io/t/unable-to-publish-or-subscribe-rostopics-using-mavlink-with-gazebo-and-px4-getting-errors/3166/1 "2017-04-30T02:14:50Z")

</div>

Hello ,  
I am newbie to PX4 , I have installed gazebo , and Cloned the Firmware.

I am trying to publish ros topics. But I am getting the Errors .

Steps I followed :

Terminal1 :

roslaunch mavros px4.launch fcu\_url:=“udp://:14540@127.0.0.1:14557”

Terminal2 :

source Tools/setup\_gazebo.bash $(pwd) $(pwd)/build\_posix\_sitl\_default  
export ROS\_PACKAGE\_PATH=$ROS\_PACKAGE\_PATH:$(pwd)/Tools/sitl\_gazebo  
roslaunch px4 posix\_sitl.launch

Errors which I am getting,

Terminal1 :

WARN] [1493507102.919495629]: TM: Clock skew detected (-0.019824184 s). Hard syncing clocks.  
[ERROR] [1493507113.704105243]: FCU: Accel #0 fail: TOUT!  
[ERROR] [1493507113.706679234]: FCU: Gyro #0 fail: TOUT!  
[WARN] [1493507113.944251371]: TM: Clock skew detected (0.012025608 s). Hard syncing clocks.  
[ERROR] [1493507121.030549466]: FCU: Accel #0 fail: TOUT!  
[ERROR] [1493507121.036021491]: FCU: Gyro #0 fail: TOUT!  
[ERROR] [1493507121.630152661]: FCU: Accel #0 fail: TOUT!  
[ERROR] [1493507121.634544822]: FCU: Gyro #0 fail: TOUT!  
[ERROR] [1493507122.108005687]: FCU: Accel #0 fail: TOUT!  
[ERROR] [1493507122.111951530]: FCU: Gyro #0 fail: TOUT!  
[ERROR] [1493507122.829282656]: FCU: Accel #0 fail: TOUT!  
[ERROR] [1493507122.830428095]: FCU: Gyro #0 fail: TOUT!  
[WARN] [1493507141.422615369]: TM: Clock skew detected (-0.016021096 s). Hard syncing clocks.

Terminal2 :

link] [timesync] Hard setting offset.  
WARN [mavlink] [timesync] Hard setting offset.  
WARN [mavlink] [timesync] Hard setting offset.  
WARN [mavlink] [timesync] Hard setting offset.  
WARN [mavlink] [timesync] Hard setting offset.  
WARN [mavlink] [timesync] Hard setting offset.  
WARN [mavlink] [timesync] Hard setting offset.  
WARN [mavlink] [timesync] Hard setting offset.  
WARN [mavlink] [timesync] Hard setting offset.  
WARN [mavlink] [timesync] Hard setting offset.  
ERROR [sensors] Accel #0 fail: TOUT!  
ERROR [sensors] Gyro #0 fail: TOUT!  
WARN [mavlink] [timesync] Hard setting offset.  
WARN [mavlink] [timesync] Hard setting offset.  
WARN [mavlink] [timesync] Hard setting offset.  
WARN [mavlink] [timesync] Hard setting offset.  
WARN [mavlink] [timesync] Hard setting offset.

Please kindly help me with this issue.

Thank you!!