Fix import oustide of control room

chro.py

@@ -12,14 +12,6 @@ from time import sleep
 from tango import DeviceProxy
 from scipy.optimize import curve_fit
 
-#%% Init
-
-tuneX = DeviceProxy("ans/rf/bbfdataviewer.1-tunex")
-tuneZ = DeviceProxy("ans/rf/bbfdataviewer.2-tunez")
-RF = DeviceProxy('ANS/RF/MasterClock')
-service_locker = DeviceProxy("ANS/CA/SERVICE-LOCKER-MATLAB")
-fofb_watcher = DeviceProxy("ANS/DG/FOFB-WATCHER")
-
 #%% chroma measurement
 
 def chroma_measurement(N_step_delta=5,
@@ -56,6 +48,13 @@ def chroma_measurement(N_step_delta=5,
         Vertical tune measured.
 
     """
+    # Init devices
+    tuneX = DeviceProxy("ans/rf/bbfdataviewer.1-tunex")
+    tuneZ = DeviceProxy("ans/rf/bbfdataviewer.2-tunez")
+    RF = DeviceProxy('ANS/RF/MasterClock')
+    service_locker = DeviceProxy("ANS/CA/SERVICE-LOCKER-MATLAB")
+    fofb_watcher = DeviceProxy("ANS/DG/FOFB-WATCHER")
+    
     # Parameters
     alphac = 4.1819e-04
     sleep_time_RF_change = 5 # second