diff --git a/hardware_system.py b/hardware_system.py
index ad80054557891e40c9eb1d8d6fbffcd3b831f77b..06cf621d58e410c7aad38b45b5878ee2f4d5a3cf 100644
--- a/hardware_system.py
+++ b/hardware_system.py
@@ -68,6 +68,7 @@ class OhmPiHardware:
         self.readings = np.array([])  # time series of acquired data
         self._start_time = None  # time of the beginning of a readings acquisition
         self._pulse = 0  # pulse number
+        self.mux_barrier = Barrier(len(self.mux_boards)+1)
 
     def _clear_values(self):
         self.readings = np.array([])