Valve blks2_valve from grc_gnuradio import blks2 as grc_blks2 grc_blks2.valve(item_size=$type.size*$vlen, open=bool($open)) set_open(bool($open)) Type type enum Open open 0 raw Vec Length vlen 1 int $vlen > 0 in $type $vlen $num_inputs out $type $vlen $num_outputs Connect output to input when valve is closed (not open).