ABAP Timer - Part 1

Timer?! Wonder why we need this in ABAP?

Here's the example of user requirement in one line:

Real time data is needed when user is viewing this ALV report for better business decisions.

Okay, not really "real-time". For my case, 3 minutes interval is the way.

There are 2 ways to achieve that requirement:

1. Function module RFC_PING_AND_WAIT

2. Class CL_GUI_TIMER