You can achieve the same with a combination of a 'OR' and a 'Memory/Delay' block.
If the 'Memory' block is connected in feedback to one of the inputs of the 'OR' block, once the output of the 'OR' block becomes high(1), this value is stored by the 'Memory' block. In the next time step, regardless of the other input, the 'OR' block will continue to output a high value because it receives the stored high value from the 'Memory' block as one of its inputs. Consequently, once set to high, the output of the 'OR' block remains high as this goes on in a cycle.
The connection is shown as follows:
Hope this answers your question. Thanks!
