cannot connect to ur5

edit

Are you trying to connect to the robot using the text box in the red rectangle below?

If you are, then that won't work. That is only used for connecting to a MongoDB server.

You'll want to connect using the provided launch files. Something like:

roslaunch ur_bringup ur5_bringup.launch robot_ip:=$IP_OF_YOUR_ROBOT

Or, if you're using the ur_modern_driver (which you should):

roslaunch ur_modern_driver ur5_bringup.launch robot_ip:=$IP_OF_YOUR_ROBOT

That should start the driver, and you can now follow the rest of the tutorial / readme.

Edit:

[..] the port number was 30002,should it be 33829?

No. You should not use the RViz plugin at all to connect to the robot. Only the driver can connect to the robot, nothing else.

Yes ,I am using ur_modern_driver. I should bringup ur5 by roslaunch ur_modern_driver ur5_bringup.launch robot_ip:=192.168.1.111 [reverse_port:=33829], is that right?

No, that is not correct. If you don't know what value you should use for reverse_port, than I'm pretty sure you don't need it.

Don't use reverse_port, it's not needed if you don't have multiple robots.