The output (Q) is disabled after an adjustable delay once the input (Tr) has been switched off.
A rising edge at the input Tr activates the output Q. A falling edge at the input Tr switches Q off after a duration which is set by the parameter T. 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 and a falling edge will deactivate after delay Tagain.
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).