Universal Robots Forum

ProfiNet reconnection issues

Hello to all,

we often stumble upon the same problem with ProfiNet communication between our PLC and three Universal Robots UR 16e.

During normal startup of all components the ProfiNet communication works.

However, if we work on the PLC code and the PLC is restarted,
it often happens that the UR robots does not reconnect to the ProfiNet master after the PLC is restarted, see picture.

  1. Request via PN-DCP from PLC before start of measurement already done
  2. Response to PN_DCP request (Ident Request) - ok
  3. UR reports its IP address to the controller
  4. Controller wants to establish connection (Connect Request)
  5. Since there is no connection response, the controller asks again 7 seconds later, but there is no response.

This problem occurs quite often and cannot be solved by deactivating and activating the ProfiNet fieldbus in the installation tab.

To solve the problem we need to disable the ProfiNet fieldbus, change the IP address of the robot and then re-enable the ProfiNet fieldbus.

Some information about our setup:

We have three UR 16e Robots running the latest URSoftware 5.9.4.103111232 (Oct 20 2020)
We use a SEW UHX65A with a Hilcher ProfiNet Master Stack.

We have remote control activated, to start, stop and pause the robot program over ProfiNet
Sometimes we also restart the PLC while a robot program is running idle.

I hope this will help to solve that issue.
If you need additional information please contact me.

With kind regards Jan