Contact is possible without passing a function?

Hi all,

I have a doubt.
Currently my imp performs imp.scanwifinetworks () and sends the result to the agent. However wanted him to do this process every x time.

For this I have to implement imp.wakeup with time I want.
My question is if after firing the agent through agent.send (“test”, {net = imp.scanwifinetworks ()}) the agent may trigger the device through device.send (“ping”, {}).
Can trigger the device without sending function?