The Latching Relay node sends 1 to the output when the input Set is set to 1 and sends 0 to the output when the input Reset is set to 1. When both Set and Reset are 0, the previous state of the output is mantained.
The Behaviour property determines whether Set or Reset must be dominant when both of them are 1.

 Behavior of node when Set input is dominant

Behavior of node when Set input is dominant

 Behavior of node when Reset input is dominant

Behavior of node when Reset input is dominant