diff --git a/mbtrack2/tracking/monitors/plotting.py b/mbtrack2/tracking/monitors/plotting.py
index d59d35996a2b5854502d3b8406736f34be49f22e..5f256b91974cc7b73bc0f2a5bbe2f1593af40116 100644
--- a/mbtrack2/tracking/monitors/plotting.py
+++ b/mbtrack2/tracking/monitors/plotting.py
@@ -1076,7 +1076,7 @@ def streak_beamspectrum(filename, dim="tau", f0=None, log_scale=True, fmin=None,
     return fig
 
 def plot_cavitydata(filename, cavity_name, phasor="cavity", 
-                    plot_type="mean", bunch_number=0, turn=None, cm_lim=None,
+                    plot_type="bunch", bunch_number=0, turn=None, cm_lim=None,
                     show_objective=False):
     """
     Plot data recorded by CavityMonitor.
@@ -1092,8 +1092,6 @@ def plot_cavitydata(filename, cavity_name, phasor="cavity",
         "ig".
     plot_type : str, optional
         Type of plot:
-            - "mean" plots the mean phasor voltage and angle versus time for 
-            non empty bunches.
             - "bunch" plots the phasor voltage and angle versus time for a 
             given bunch.
             - "turn" plots the phasor voltage and ange versus bunch index for
@@ -1104,7 +1102,11 @@ def plot_cavitydata(filename, cavity_name, phasor="cavity",
             time.
             - "detune" or "psi" plots the detuning or tuning angle versus time.
             - "power" plots the generator, cavity, beam and reflected power
-            versus time.
+            versus time. Needs BeamMonitor data with same save_every as 
+            CavityMonitor.
+            - "mean" plots the mean phasor voltage and angle versus time for 
+            non empty bunches. Needs BeamMonitor data with same save_every as 
+            CavityMonitor.
     bunch_number : int, optional
         Bunch number to select. The default is 0.
     turn : int, optional
@@ -1143,7 +1145,7 @@ def plot_cavitydata(filename, cavity_name, phasor="cavity",
             try:
                 bunch_index = (file["Beam"]["current"][:,0] != 0).nonzero()[0]
             except:
-                print("Beam monitor is needed to show mean voltage.")
+                ValueError("Beam monitor is needed to show mean voltage.")
             data = [np.mean(cavity_data["cavity_phasor_record"][bunch_index,:],0), 
                     np.mean(cavity_data["beam_phasor_record"][bunch_index,:],0),
                     np.mean(cavity_data["generator_phasor_record"][bunch_index,:],0),