diff --git a/test/pyadpt-81.py b/test/pyadpt-81.py
index 6ff7021..7fa0d45 100644
--- a/test/pyadpt-81.py
+++ b/test/pyadpt-81.py
@@ -2,6 +2,24 @@
 # -*- coding: utf-8 -*-
 
 import pEp
+import time
+
+def user_message_to_send(msg):
+    print("User defined callback implementation")
+
+def start_stop_sync(duration):
+    pEp.start_sync()
+    time.sleep(duration)
+    pEp.shutdown_sync()
 
 dir(pEp)
-pEp.is_sync_active()
\ No newline at end of file
+# test default callback
+start_stop_sync(1)
+# test user defined callback
+pEp.message_to_send = user_message_to_send
+start_stop_sync(1)
+
+pEp.start_sync()
+while(True):
+    print("is_sync_active: {}".format(pEp.is_sync_active()))
+    time.sleep(1)
\ No newline at end of file