@bogle The FOG server talks to the target computer via the FOG Client/service. That service has a check in interval that is set in the fog settings. So the default may be 5 minutes (300 seconds), so if you issue a task to the target computer it could take up to 5 minutes before the target system reacts.
Also on the fog up/down indicator it doesn’t use a ping, but a connect to port 445 to confirm the system is up or not. If your windows firewall is blocking connections to port 445 then fog will assume its down.