Universal Robots Forum

Handling the error from daemon process in program node


if there is any exception/failure in the communication between URCap program node and a backend daemon process, can anyone suggest how to handle the exception in the program node. My objective is that the cobot program should not be stopped because of this error.

In the generateScript() method, the script code (python) should have exception handling mechanism. We couldn’t add the required code in python script to handle the exception.

any pointers much appreciated…


on first thought i would suggest using interprocess communication. sth. like this

Hi Michael,

Thanks for your response. The referred link doesn’t solve my problem. I don’t want to create a sub-process thread for the IPC. Its too much overhead for the python process which is executing the robot program runtime.

Ok i misunderstood your question, thought you want to catch the exception in the java layer.

To communicate with the daemon through urscript, you can use a tcp socket written in urscript, see the urcap manual section 9.0 and 9.2:

„ /etc/service directory contains links to the URCap daemon executables currently running. If a daemon executable has a link present but is in fact not running, the ERROR state will be returned upon querying the daemon’s state.“


Hi Michael,

Thanks for your response. Much appreciated.