PL/SQL :: How To Write Proc That Checks Remote DB

I have a one critical remote PROD database that I want to check every 10 mins for its connectivity. If connection fails then an email & SMS is sent to me. My question is what is the best way to check if the remote database is up and running?

Can I use sqlplus system/manager@PROD? But sometimes this took so long and hanging. I want the fastest response time? How do I write a pl/sql proc check connection? That do something like the ff:

I created a table for my tnsname.ora entries.

cursor is c1 select dbname from tnsnames_tbl;
begin
connect system/manager@c1.dbname;
print c1.dbname || 'DB Connection OK';
exception
when others;
print c1.dbname || 'DB Connection Not OK';
end;
end;