upon startup the robot is supposed to report into the hub, most likely that process if failing.
ensure the ports are open in both directions
to test remote into hub and telnet <robot ip address>:48000 and then 48002
then remote into robot and try it with the hub's IP address.
At the problem robot:
stop the nimsoft robot watcher service
modify robot.cfg
default location: C:\Program Files (x86)\Nimsoft\robot
set loglevel = 3
save
start the nimsoft robot watcher service
check controller.log, default location same as above.
Firewall Port Reference
https://docops.ca.com/ca-unified-infrastructure-management/8-5-1/en/installing-ca-uim/pre-installation-planning/firewall-port-reference
What are the ports used by Nimsoft?
Document ID : KB000034617
https://comm.support.ca.com/kb/what-are-the-ports-used-by-nimsoft/kb000034617