Is it possible to set a machine online/offline via WCC?
Check on the "Dashboard" tab if you have "Machines" widget.
On the "Machines" widget, you can select a machine and perform action "Send Machine Online Event" or "Send Machine Offline Event".
In case you don't have the "Machines" widget on "Dashboard", you can add it as follows.
1. Login into EEM UI with EiamAdmin user and selecting application WCC0004.
2. Select "Manage Policies"
3. Select "WidgetAccess"
4. Check if your user and/or group has flag set for "MonitoringMachines"