Universal Robots UR3 Service Manual page 70

5. Service and Replacement of Parts
To replace Safety Control Board in Controller box:
1. Check that the software on the robot is not older than the firmware version on the SCB.
If the software on the robot is older, error C203A0 will be displayed.
The SCB firmware version can be found on the Ethernet connector.
This can also be found in the "About" menu.
Shortcut to "About", by clicking on the UR logo in the top right corner of the screen is
available from software version 3.2.18642
UR3 64 Service Manual