--- /dev/null
+<?xml version="1.0"?>
+<!--
+###################################################
+##Threshold
+###################################################
+ -->
+<block>
+ <name>Threshold</name>
+ <key>gr_threshold_ff</key>
+ <import>from gnuradio import gr</import>
+ <make>gr.threshold_ff($low, $high, $init)</make>
+ <callback>set_hi($high)</callback>
+ <callback>set_lo($low)</callback>
+ <param>
+ <name>Low</name>
+ <key>low</key>
+ <value>-100</value>
+ <type>real</type>
+ </param>
+ <param>
+ <name>High</name>
+ <key>high</key>
+ <value>100</value>
+ <type>real</type>
+ </param>
+ <param>
+ <name>Initial State</name>
+ <key>init</key>
+ <value>0</value>
+ <type>real</type>
+ </param>
+ <sink>
+ <name>in</name>
+ <type>float</type>
+ </sink>
+ <source>
+ <name>out</name>
+ <type>float</type>
+ </source>
+</block>