Threading in Timers

In my Application, I want to insert some values into the database for each and every second.
This application will have to connect to different systems(Clients).

I wrote this code in timer running for each second(1000ms). Inside timer i put a loop, iterating for number of clients, if any one of them is unable to connect to the server system,
The remaining clients will have to wait for some time, then the loop will not run for each second.

So i want to use threading concept, but i am not sure how to use threading in timers, so please help me with this..

Thanks in advance