Switch On and Off Delay
A rising edge at the input Tr activates the output Q after a duration which is set by the parameter TH. If the pulse at Tr is shorter than TH then Q will not change state.
A falling edge at the input Tr switches Q off after a duration which is set by the parameter TL. The delay time of the block is restarted with each rising edge at Tr.
When R is then triggered the block timer is reset and the output Q is disabled. Then a new rising edge at the input Tr will activate the output after delay TH and a falling edge will deactivate after delay TL again.
The block can be set to be retentive, this is done by clicking on the battery symbol to set the red NOT dot on the block (input is by default inactive).