Cacti - ping graph = how to make ?? [ anyone know? ]

Hello.
Does anyone know how to make a graph of pings in cacti?
I need to do statistics on ping between Mikrotik’s.
Does anyone have made such a chart?

My configuration is as follows:
mikrotik:

devices:

Graph Management:

Data Sources:

This what I’m not working, shows all the time “packet loss”
could someone hint?