Enterprise Manager :: OEM - Black Out Target DB From Script

I have a script that can issue a node-level blackout and code to remove it.

Add
===
$AGENT_HOME/bin/emctl start blackout $blackout_name -nodelevel

Drop
====
$AGENT_HOME/bin/emctl status blackout | grep Blackoutname |
sed -e "s:.*Blackoutname = ::" -e 's/(.*//' |
while read blackout_name
do
$AGENT_HOME/bin/emctl stop blackout $blackout_name
done

Is there a command or code I can use within a shell script to do the same (add/drop) for only a single Target DB?