diff --git a/daq/src/mxlibs3/non_standard.py b/daq/src/mxlibs3/non_standard.py
index 02dbba57..a5b64ae2 100644
--- a/daq/src/mxlibs3/non_standard.py
+++ b/daq/src/mxlibs3/non_standard.py
@@ -246,7 +246,11 @@ class NonStandard(object):
         else:
             speed = self.get_speed()
             curp = self.position
-            timeout = self.__timeout_margin + (abs(curp - self.__target_pos) / speed)
+            if curp is None or self.__target_pos is None or speed is None:
+                timeout = self.__timeout_margin
+                raise RuntimeWarning("can't calculate timeout, ABR may be disconnected")
+            else:
+                timeout = self.__timeout_margin + (abs(curp - self.__target_pos) / speed)
         return timeout
 
     def wait(self):