diff --git a/mcstas-comps/union/Union_abs_logger_1D_space.comp b/mcstas-comps/union/Union_abs_logger_1D_space.comp
index cd1cb0ff4..34b975f5b 100644
--- a/mcstas-comps/union/Union_abs_logger_1D_space.comp
+++ b/mcstas-comps/union/Union_abs_logger_1D_space.comp
@@ -67,6 +67,7 @@
 * order_volume:    [1] Only log rays that have scattered n times in the same geometry, -1 for all orders
 * logger_conditional_extend_index: [1] If a conditional is used with this logger, the result of each conditional calculation can be made available in extend as a array called "logger_conditional_extend", and one would then access logger_conditional_extend[n] if logger_conditional_extend_index is set to n
 * init:              [string] name of Union_init component (typically "init", default)
+* nowritefile:     [1]      If set, logger will skip writing to disk
 *
 * CALCULATED PARAMETERS:
 *
@@ -81,7 +82,7 @@ DEFINE COMPONENT Union_abs_logger_1D_space
 
 SETTING PARAMETERS(string target_geometry="NULL",
                    yheight, n=100,
-                   string filename="NULL", order_total=-1, order_volume=-1, logger_conditional_extend_index=-1, string init="init")
+                   string filename="NULL", order_total=-1, order_volume=-1, logger_conditional_extend_index=-1, string init="init", int nowritefile=0)
 
 
 /* Neutron parameters: (x,y,z,vx,vy,vz,t,sx,sy,sz,p) */
@@ -519,10 +520,12 @@ TRACE
 SAVE
 %{
   // Write to disk
-  DETECTOR_OUT_1D (this_abs_storage.Detector_1D.title_string, this_abs_storage.Detector_1D.string_axis, this_abs_storage.Detector_1D.string_axis_value,
-                   this_abs_storage.Detector_1D.string_axis_short, this_abs_storage.Detector_1D.min, this_abs_storage.Detector_1D.max,
-                   this_abs_storage.Detector_1D.bins, &this_abs_storage.Detector_1D.Array_N[0], &this_abs_storage.Detector_1D.Array_p[0],
-                   &this_abs_storage.Detector_1D.Array_p2[0], this_abs_storage.Detector_1D.Filename);
+  if (!nowritefile) {
+    DETECTOR_OUT_1D (this_abs_storage.Detector_1D.title_string, this_abs_storage.Detector_1D.string_axis, this_abs_storage.Detector_1D.string_axis_value,
+                     this_abs_storage.Detector_1D.string_axis_short, this_abs_storage.Detector_1D.min, this_abs_storage.Detector_1D.max,
+                     this_abs_storage.Detector_1D.bins, &this_abs_storage.Detector_1D.Array_N[0], &this_abs_storage.Detector_1D.Array_p[0],
+                     &this_abs_storage.Detector_1D.Array_p2[0], this_abs_storage.Detector_1D.Filename);
+  }
 %}
 
 FINALLY
diff --git a/mcstas-comps/union/Union_abs_logger_1D_space_event.comp b/mcstas-comps/union/Union_abs_logger_1D_space_event.comp
index 5fdd6587c..758e6d50f 100644
--- a/mcstas-comps/union/Union_abs_logger_1D_space_event.comp
+++ b/mcstas-comps/union/Union_abs_logger_1D_space_event.comp
@@ -77,6 +77,7 @@
 * order_volume:    [1] Only log rays that have scattered n times in the same geometry, -1 for all orders
 * logger_conditional_extend_index: [1] If a conditional is used with this logger, the result of each conditional calculation can be made available in extend as a array called "logger_conditional_extend", and one would then access logger_conditional_extend[n] if logger_conditional_extend_index is set to n
 * init:              [string] name of Union_init component (typically "init", default)
+* nowritefile:     [1]      If set, logger will skip writing to disk
 *
 * CALCULATED PARAMETERS:
 *
@@ -90,7 +91,7 @@
 DEFINE COMPONENT Union_abs_logger_1D_space_event
 
 SETTING PARAMETERS(string target_geometry="NULL", yheight, int n, int fake_event=0,
-                   string filename="NULL", order_total=-1, order_volume=-1, logger_conditional_extend_index=-1, string init="init")
+                   string filename="NULL", order_total=-1, order_volume=-1, logger_conditional_extend_index=-1, string init="init", int nowritefile=0)
 
 
 /* Neutron parameters: (x,y,z,vx,vy,vz,t,sx,sy,sz,p) */
@@ -615,7 +616,9 @@ TRACE
 
 SAVE
 %{
-  Monitor_nD_Save (&(this_abs_storage.DEFS), &(this_abs_storage.Vars));
+  if (!nowritefile) {
+    Monitor_nD_Save (&(this_abs_storage.DEFS), &(this_abs_storage.Vars));
+  }
 %}
 
 FINALLY
diff --git a/mcstas-comps/union/Union_abs_logger_1D_space_tof.comp b/mcstas-comps/union/Union_abs_logger_1D_space_tof.comp
index b321f4c2d..0a70dac09 100644
--- a/mcstas-comps/union/Union_abs_logger_1D_space_tof.comp
+++ b/mcstas-comps/union/Union_abs_logger_1D_space_tof.comp
@@ -70,6 +70,7 @@
 * order_volume:    [1] Only log rays that have scattered n times in the same geometry, -1 for all orders
 * logger_conditional_extend_index: [1] If a conditional is used with this logger, the result of each conditional calculation can be made available in extend as a array called "logger_conditional_extend", and one would then access logger_conditional_extend[n] if logger_conditional_extend_index is set to n
 * init:              [string] name of Union_init component (typically "init", default)
+* nowritefile:     [1]      If set, logger will skip writing to disk
 *
 * CALCULATED PARAMETERS:
 *
@@ -85,7 +86,7 @@ DEFINE COMPONENT Union_abs_logger_1D_space_tof
 SETTING PARAMETERS(string target_geometry="NULL",
                    yheight, n=0.2,
                    time_min=0, time_max=1, time_bins=100,
-                   string filename="NULL", order_total=-1, order_volume=-1, logger_conditional_extend_index=-1, string init="init")
+                   string filename="NULL", order_total=-1, order_volume=-1, logger_conditional_extend_index=-1, string init="init", int nowritefile=0)
 
 
 /* Neutron parameters: (x,y,z,vx,vy,vz,t,sx,sy,sz,p) */
@@ -580,10 +581,12 @@ TRACE
 SAVE
 %{
   // Write to disk
-  DETECTOR_OUT_2D (this_abs_storage.Detector_2D.title_string, this_abs_storage.Detector_2D.string_axis_1, this_abs_storage.Detector_2D.string_axis_2,
-                   this_abs_storage.Detector_2D.D1min, this_abs_storage.Detector_2D.D1max, this_abs_storage.Detector_2D.D2min, this_abs_storage.Detector_2D.D2max,
-                   this_abs_storage.Detector_2D.bins_1, this_abs_storage.Detector_2D.bins_2, *this_abs_storage.Detector_2D.Array_N,
-                   *this_abs_storage.Detector_2D.Array_p, *this_abs_storage.Detector_2D.Array_p2, this_abs_storage.Detector_2D.Filename);
+  if (!nowritefile) {
+    DETECTOR_OUT_2D (this_abs_storage.Detector_2D.title_string, this_abs_storage.Detector_2D.string_axis_1, this_abs_storage.Detector_2D.string_axis_2,
+                     this_abs_storage.Detector_2D.D1min, this_abs_storage.Detector_2D.D1max, this_abs_storage.Detector_2D.D2min, this_abs_storage.Detector_2D.D2max,
+                     this_abs_storage.Detector_2D.bins_1, this_abs_storage.Detector_2D.bins_2, *this_abs_storage.Detector_2D.Array_N,
+                     *this_abs_storage.Detector_2D.Array_p, *this_abs_storage.Detector_2D.Array_p2, this_abs_storage.Detector_2D.Filename);
+  }
 %}
 
 FINALLY
diff --git a/mcstas-comps/union/Union_abs_logger_1D_space_tof_to_lambda.comp b/mcstas-comps/union/Union_abs_logger_1D_space_tof_to_lambda.comp
index 4469011a5..23caf39d6 100644
--- a/mcstas-comps/union/Union_abs_logger_1D_space_tof_to_lambda.comp
+++ b/mcstas-comps/union/Union_abs_logger_1D_space_tof_to_lambda.comp
@@ -101,6 +101,7 @@
 * order_volume:       [1]      Only log rays that have scattered n times in the same geometry, -1 for all orders
 * logger_conditional_extend_index: [1] If a conditional is used with this logger, the result of each conditional calculation can be made available in extend as a array called "logger_conditional_extend", and one would then access logger_conditional_extend[n] if logger_conditional_extend_index is set to n
 * init:               [string] Name of Union_init component (typically "init", default)
+* nowritefile:        [1]      If set, logger will skip writing to disk
 *
 * CALCULATED PARAMETERS:
 *
@@ -119,7 +120,7 @@ SETTING PARAMETERS(string target_geometry="NULL",
                    lambda_m_min=-1, lambda_m_max=-1, lambda_m_bins=-1,
                    lambda_t_min=-1, lambda_t_max=-1, lambda_t_bins=-1,
                    relative_measured=0, relative_min=0.5, relative_max=1.5, relative_bins=100,
-                   string filename="NULL", order_total=-1, order_volume=-1, logger_conditional_extend_index=-1, string init="init")
+                   string filename="NULL", order_total=-1, order_volume=-1, logger_conditional_extend_index=-1, string init="init", int nowritefile=0)
 
 
 /* Neutron parameters: (x,y,z,vx,vy,vz,t,sx,sy,sz,p) */
@@ -784,10 +785,12 @@ TRACE
 SAVE
 %{
   // Write to disk
-  DETECTOR_OUT_2D (this_abs_storage.Detector_2D.title_string, this_abs_storage.Detector_2D.string_axis_1, this_abs_storage.Detector_2D.string_axis_2,
-                   this_abs_storage.Detector_2D.D1min, this_abs_storage.Detector_2D.D1max, this_abs_storage.Detector_2D.D2min, this_abs_storage.Detector_2D.D2max,
-                   this_abs_storage.Detector_2D.bins_1, this_abs_storage.Detector_2D.bins_2, *this_abs_storage.Detector_2D.Array_N,
-                   *this_abs_storage.Detector_2D.Array_p, *this_abs_storage.Detector_2D.Array_p2, this_abs_storage.Detector_2D.Filename);
+  if (!nowritefile) {
+    DETECTOR_OUT_2D (this_abs_storage.Detector_2D.title_string, this_abs_storage.Detector_2D.string_axis_1, this_abs_storage.Detector_2D.string_axis_2,
+                     this_abs_storage.Detector_2D.D1min, this_abs_storage.Detector_2D.D1max, this_abs_storage.Detector_2D.D2min, this_abs_storage.Detector_2D.D2max,
+                     this_abs_storage.Detector_2D.bins_1, this_abs_storage.Detector_2D.bins_2, *this_abs_storage.Detector_2D.Array_N,
+                     *this_abs_storage.Detector_2D.Array_p, *this_abs_storage.Detector_2D.Array_p2, this_abs_storage.Detector_2D.Filename);
+  }
 %}
 
 FINALLY
diff --git a/mcstas-comps/union/Union_abs_logger_1D_time.comp b/mcstas-comps/union/Union_abs_logger_1D_time.comp
index 4023fe0cf..5fac10a8a 100644
--- a/mcstas-comps/union/Union_abs_logger_1D_time.comp
+++ b/mcstas-comps/union/Union_abs_logger_1D_time.comp
@@ -71,6 +71,7 @@
 * init:            [string] name of Union_init component (typically "init", default)
 * time_min:        [s] Minimum time to log
 * time_max:        [s] Maximum time to log
+* nowritefile:     [1]      If set, logger will skip writing to disk
 *
 * OUTPUT PARAMETERS:
 *
@@ -85,7 +86,7 @@ DEFINE COMPONENT Union_abs_logger_1D_time
 DEFINITION PARAMETERS ()
 SETTING PARAMETERS(string target_geometry="NULL",
                    time_min=0, time_max, n=100,
-                   string filename="NULL", order_total=-1, order_volume=-1, logger_conditional_extend_index=-1, string init="init")
+                   string filename="NULL", order_total=-1, order_volume=-1, logger_conditional_extend_index=-1, string init="init", int nowritefile=0)
 OUTPUT PARAMETERS ()
 
 /* Neutron parameters: (x,y,z,vx,vy,vz,t,sx,sy,sz,p) */
@@ -503,10 +504,12 @@ TRACE
 SAVE
 %{
   // Write to disk
-  DETECTOR_OUT_1D (this_abs_storage.Detector_1D.title_string, this_abs_storage.Detector_1D.string_axis, this_abs_storage.Detector_1D.string_axis_value,
-                   this_abs_storage.Detector_1D.string_axis_short, this_abs_storage.Detector_1D.min, this_abs_storage.Detector_1D.max,
-                   this_abs_storage.Detector_1D.bins, &this_abs_storage.Detector_1D.Array_N[0], &this_abs_storage.Detector_1D.Array_p[0],
-                   &this_abs_storage.Detector_1D.Array_p2[0], this_abs_storage.Detector_1D.Filename);
+  if (!nowritefile) {
+    DETECTOR_OUT_1D (this_abs_storage.Detector_1D.title_string, this_abs_storage.Detector_1D.string_axis, this_abs_storage.Detector_1D.string_axis_value,
+                     this_abs_storage.Detector_1D.string_axis_short, this_abs_storage.Detector_1D.min, this_abs_storage.Detector_1D.max,
+                     this_abs_storage.Detector_1D.bins, &this_abs_storage.Detector_1D.Array_N[0], &this_abs_storage.Detector_1D.Array_p[0],
+                     &this_abs_storage.Detector_1D.Array_p2[0], this_abs_storage.Detector_1D.Filename);
+  }
 %}
 
 FINALLY
diff --git a/mcstas-comps/union/Union_abs_logger_2D_space.comp b/mcstas-comps/union/Union_abs_logger_2D_space.comp
index 69c24cf64..50d62142f 100644
--- a/mcstas-comps/union/Union_abs_logger_2D_space.comp
+++ b/mcstas-comps/union/Union_abs_logger_2D_space.comp
@@ -77,6 +77,7 @@
 * order_volume:    [1]      Only log rays that have scattered n times in the same geometry, -1 for all orders
 * logger_conditional_extend_index: [1] If a conditional is used with this logger, the result of each conditional calculation can be made available in extend as a array called "logger_conditional_extend", and one would then access logger_conditional_extend[n] if logger_conditional_extend_index is set to n
 * init:            [string] Name of Union_init component (typically "init", default)
+* nowritefile:     [1]      If set, logger will skip writing to disk
 *
 * CALCULATED PARAMETERS:
 *
@@ -92,7 +93,7 @@ DEFINE COMPONENT Union_abs_logger_2D_space
 SETTING PARAMETERS(string target_geometry="NULL",
                    string D_direction_1="x", D1_min=-0.2, D1_max=5, n1=0.2,
                    string D_direction_2="z", D2_min=-0.2, D2_max=5, n2=0.2,
-                   string filename="NULL", order_total=-1, order_volume=-1, logger_conditional_extend_index=-1, string init="init")
+                   string filename="NULL", order_total=-1, order_volume=-1, logger_conditional_extend_index=-1, string init="init", int nowritefile=0)
 
 
 /* Neutron parameters: (x,y,z,vx,vy,vz,t,sx,sy,sz,p) */
@@ -641,10 +642,12 @@ TRACE
 SAVE
 %{
   // Write to disk
-  DETECTOR_OUT_2D (this_abs_storage.Detector_2D.title_string, this_abs_storage.Detector_2D.string_axis_1, this_abs_storage.Detector_2D.string_axis_2,
-                   this_abs_storage.Detector_2D.D1min, this_abs_storage.Detector_2D.D1max, this_abs_storage.Detector_2D.D2min, this_abs_storage.Detector_2D.D2max,
-                   this_abs_storage.Detector_2D.bins_1, this_abs_storage.Detector_2D.bins_2, *this_abs_storage.Detector_2D.Array_N,
-                   *this_abs_storage.Detector_2D.Array_p, *this_abs_storage.Detector_2D.Array_p2, this_abs_storage.Detector_2D.Filename);
+  if (!nowritefile) {
+    DETECTOR_OUT_2D (this_abs_storage.Detector_2D.title_string, this_abs_storage.Detector_2D.string_axis_1, this_abs_storage.Detector_2D.string_axis_2,
+                     this_abs_storage.Detector_2D.D1min, this_abs_storage.Detector_2D.D1max, this_abs_storage.Detector_2D.D2min, this_abs_storage.Detector_2D.D2max,
+                     this_abs_storage.Detector_2D.bins_1, this_abs_storage.Detector_2D.bins_2, *this_abs_storage.Detector_2D.Array_N,
+                     *this_abs_storage.Detector_2D.Array_p, *this_abs_storage.Detector_2D.Array_p2, this_abs_storage.Detector_2D.Filename);
+  }
 %}
 
 FINALLY
diff --git a/mcstas-comps/union/Union_abs_logger_event.comp b/mcstas-comps/union/Union_abs_logger_event.comp
index 3d325c0f2..36b4b28b6 100644
--- a/mcstas-comps/union/Union_abs_logger_event.comp
+++ b/mcstas-comps/union/Union_abs_logger_event.comp
@@ -73,6 +73,7 @@
 * ybins:           [1] Number of bins along y in logging volume
 * zbns:            [1] Number of bins along z in logging volume
 * init:            [string] Name of Union_init component (typically "init", default)
+* nowritefile:     [1]      If set, logger will skip writing to disk
 *
 * CALCULATED PARAMETERS:
 *
@@ -87,7 +88,7 @@ DEFINE COMPONENT Union_abs_logger_event
 
 SETTING PARAMETERS(string target_geometry="NULL", string filename="NULL",
                    xwidth=0, xbins=0, yheight=0, ybins=0, zdepth=0, zbins=0,
-                   order_total=-1, order_volume=-1, logger_conditional_extend_index=-1, string init="init")
+                   order_total=-1, order_volume=-1, logger_conditional_extend_index=-1, string init="init", int nowritefile=0)
 
 
 /* Neutron parameters: (x,y,z,vx,vy,vz,t,sx,sy,sz,p) */
@@ -693,7 +694,9 @@ TRACE
 
 SAVE
 %{
-  Monitor_nD_Save (&this_abs_storage.DEFS, &this_abs_storage.Vars);
+  if (!nowritefile) {
+    Monitor_nD_Save (&this_abs_storage.DEFS, &this_abs_storage.Vars);
+  }
 %}
 
 FINALLY
diff --git a/mcstas-comps/union/Union_abs_logger_nD.comp b/mcstas-comps/union/Union_abs_logger_nD.comp
index d765f1e0f..85f2623e9 100644
--- a/mcstas-comps/union/Union_abs_logger_nD.comp
+++ b/mcstas-comps/union/Union_abs_logger_nD.comp
@@ -102,7 +102,7 @@
 * username9: [str]       Name assigned to User9
 * restore_neutron: [0|1] Not functional for Union version
 * geometry: [str]        Name of an OFF file to specify a complex geometry detector
-* nowritefile: [1]       Not functional for Union version
+* nowritefile: [1]       If set, logger will skip writing to disk
 * nexus_bins: [1]        NeXus mode only: store component BIN information <br>(-1 disable, 0 enable for list mode monitor, 1 enable for any montor)
 *
 * OUTPUT PARAMETERS:
diff --git a/mcstas-comps/union/Union_logger_1D.comp b/mcstas-comps/union/Union_logger_1D.comp
index d2a0eccf9..e859b8893 100644
--- a/mcstas-comps/union/Union_logger_1D.comp
+++ b/mcstas-comps/union/Union_logger_1D.comp
@@ -58,6 +58,7 @@
 * order_volume_process: [1]      Only log rays that scatter for the n'th time in the same geometry, using the same process
 * logger_conditional_extend_index: [1] If a conditional is used with this logger, the result of each conditional calculation can be made available in extend as a array called "logger_conditional_extend", and one would then acces logger_conditional_extend[n] if logger_conditional_extend_index is set to n
 * init:                 [string] Name of Union_init component (typically "init", default)
+* nowritefile:          [1]      If set, logger will skip writing to disk
 *
 * CALCULATED PARAMETERS:
 *
@@ -70,7 +71,7 @@
 
 DEFINE COMPONENT Union_logger_1D
 
-SETTING PARAMETERS(string target_geometry="NULL", string target_process="NULL", min_value, max_value, n1=90, string variable="time",string filename="NULL", order_total=0, order_volume=0, order_volume_process=0, logger_conditional_extend_index=-1, string init="init")
+SETTING PARAMETERS(string target_geometry="NULL", string target_process="NULL", min_value, max_value, n1=90, string variable="time",string filename="NULL", order_total=0, order_volume=0, order_volume_process=0, logger_conditional_extend_index=-1, string init="init", int nowritefile=0)
 
 
 /* Neutron parameters: (x,y,z,vx,vy,vz,t,sx,sy,sz,p) */
@@ -588,10 +589,12 @@ TRACE
 SAVE
 %{
   // Write to disk
-  DETECTOR_OUT_1D (this_storage.Detector_1D.title_string, this_storage.Detector_1D.string_axis, this_storage.Detector_1D.string_axis_value,
-                   this_storage.Detector_1D.string_axis_short, this_storage.Detector_1D.min, this_storage.Detector_1D.max, this_storage.Detector_1D.bins,
-                   &this_storage.Detector_1D.Array_N[0], &this_storage.Detector_1D.Array_p[0], &this_storage.Detector_1D.Array_p2[0],
-                   this_storage.Detector_1D.Filename);
+  if (!nowritefile) {
+    DETECTOR_OUT_1D (this_storage.Detector_1D.title_string, this_storage.Detector_1D.string_axis, this_storage.Detector_1D.string_axis_value,
+                     this_storage.Detector_1D.string_axis_short, this_storage.Detector_1D.min, this_storage.Detector_1D.max, this_storage.Detector_1D.bins,
+                     &this_storage.Detector_1D.Array_N[0], &this_storage.Detector_1D.Array_p[0], &this_storage.Detector_1D.Array_p2[0],
+                     this_storage.Detector_1D.Filename);
+  }
 %}
 
 
diff --git a/mcstas-comps/union/Union_logger_2DQ.comp b/mcstas-comps/union/Union_logger_2DQ.comp
index 5fbb7104b..dfbd3bcac 100644
--- a/mcstas-comps/union/Union_logger_2DQ.comp
+++ b/mcstas-comps/union/Union_logger_2DQ.comp
@@ -60,6 +60,7 @@
 * order_volume_process: [1]      Only log rays that scatter for the n'th time in the same geometry, uwsing the same process
 * logger_conditional_extend_index: [1] If a conditional is used with this logger, the result of each conditional calculation can be made available in extend as a array called "logger_conditional_extend", and one would then acces logger_conditional_extend[n] if logger_conditional_extend_index is set to n
 * init:                 [string] Name of Union_init component (typically "init", default)
+* nowritefile:          [1]      If set, logger will skip writing to disk
 *
 * CALCULATED PARAMETERS:
 *
@@ -76,7 +77,7 @@ SETTING PARAMETERS(string target_geometry="NULL",string target_process="NULL",
     string Q_direction_1="x", Q1_min=-5,Q1_max=5, n1=90,
     string Q_direction_2="z", Q2_min=-5,Q2_max=5, n2=90,
     string filename="NULL", order_total=0, order_volume=0,
-    order_volume_process=0,logger_conditional_extend_index=-1, string init="init")
+    order_volume_process=0,logger_conditional_extend_index=-1, string init="init", int nowritefile=0)
 
 
 /* Neutron parameters: (x,y,z,vx,vy,vz,t,sx,sy,sz,p) */
@@ -669,10 +670,12 @@ TRACE
 SAVE
 %{
   // Write to disk
-  DETECTOR_OUT_2D (this_storage.Detector_2D.title_string, this_storage.Detector_2D.string_axis_1, this_storage.Detector_2D.string_axis_2,
-                   this_storage.Detector_2D.D1min, this_storage.Detector_2D.D1max, this_storage.Detector_2D.D2min, this_storage.Detector_2D.D2max,
-                   this_storage.Detector_2D.bins_1, this_storage.Detector_2D.bins_2, *this_storage.Detector_2D.Array_N, *this_storage.Detector_2D.Array_p,
-                   *this_storage.Detector_2D.Array_p2, this_storage.Detector_2D.Filename);
+  if (!nowritefile) {
+    DETECTOR_OUT_2D (this_storage.Detector_2D.title_string, this_storage.Detector_2D.string_axis_1, this_storage.Detector_2D.string_axis_2,
+                     this_storage.Detector_2D.D1min, this_storage.Detector_2D.D1max, this_storage.Detector_2D.D2min, this_storage.Detector_2D.D2max,
+                     this_storage.Detector_2D.bins_1, this_storage.Detector_2D.bins_2, *this_storage.Detector_2D.Array_N, *this_storage.Detector_2D.Array_p,
+                     *this_storage.Detector_2D.Array_p2, this_storage.Detector_2D.Filename);
+  }
 %}
 
 FINALLY
diff --git a/mcstas-comps/union/Union_logger_2D_kf.comp b/mcstas-comps/union/Union_logger_2D_kf.comp
index 1255d5db5..fd8e21413 100644
--- a/mcstas-comps/union/Union_logger_2D_kf.comp
+++ b/mcstas-comps/union/Union_logger_2D_kf.comp
@@ -61,6 +61,7 @@
 * order_volume_process: [1]      Only log rays that scatter for the n'th time in the same geometry, using the same process
 * logger_conditional_extend_index: [1] If a conditional is used with this logger, the result of each conditional calculation can be made available in extend as a array called "logger_conditional_extend", and one would then acces logger_conditional_extend[n] if logger_conditional_extend_index is set to n
 * init:                 [string] Name of Union_init component (typically "init", default)
+* nowritefile:          [1]      If set, logger will skip writing to disk
 *
 * CALCULATED PARAMETERS:
 *
@@ -73,7 +74,7 @@
 
 DEFINE COMPONENT Union_logger_2D_kf
 
-SETTING PARAMETERS(string target_geometry="NULL",string target_process="NULL", Q1_min=-5, Q1_max=5, Q2_min=-5, Q2_max=5, string Q_direction_1="x", string Q_direction_2="z",string filename="NULL", n1=90, n2=90, order_total=0,order_volume=0,order_volume_process=0,logger_conditional_extend_index=-1, string init="init")
+SETTING PARAMETERS(string target_geometry="NULL",string target_process="NULL", Q1_min=-5, Q1_max=5, Q2_min=-5, Q2_max=5, string Q_direction_1="x", string Q_direction_2="z",string filename="NULL", n1=90, n2=90, order_total=0,order_volume=0,order_volume_process=0,logger_conditional_extend_index=-1, string init="init", int nowritefile=0)
 
 
 /* Neutron parameters: (x,y,z,vx,vy,vz,t,sx,sy,sz,p) */
@@ -671,10 +672,12 @@ TRACE
 SAVE
 %{
   // Write to disk
-  DETECTOR_OUT_2D (this_storage.Detector_2D.title_string, this_storage.Detector_2D.string_axis_1, this_storage.Detector_2D.string_axis_2,
-                   this_storage.Detector_2D.D1min, this_storage.Detector_2D.D1max, this_storage.Detector_2D.D2min, this_storage.Detector_2D.D2max,
-                   this_storage.Detector_2D.bins_1, this_storage.Detector_2D.bins_2, *this_storage.Detector_2D.Array_N, *this_storage.Detector_2D.Array_p,
-                   *this_storage.Detector_2D.Array_p2, this_storage.Detector_2D.Filename);
+  if (!nowritefile) {
+    DETECTOR_OUT_2D (this_storage.Detector_2D.title_string, this_storage.Detector_2D.string_axis_1, this_storage.Detector_2D.string_axis_2,
+                     this_storage.Detector_2D.D1min, this_storage.Detector_2D.D1max, this_storage.Detector_2D.D2min, this_storage.Detector_2D.D2max,
+                     this_storage.Detector_2D.bins_1, this_storage.Detector_2D.bins_2, *this_storage.Detector_2D.Array_N, *this_storage.Detector_2D.Array_p,
+                     *this_storage.Detector_2D.Array_p2, this_storage.Detector_2D.Filename);
+  }
 %}
 
 FINALLY
diff --git a/mcstas-comps/union/Union_logger_2D_kf_time.comp b/mcstas-comps/union/Union_logger_2D_kf_time.comp
index 2e13a9d53..30c029236 100644
--- a/mcstas-comps/union/Union_logger_2D_kf_time.comp
+++ b/mcstas-comps/union/Union_logger_2D_kf_time.comp
@@ -65,6 +65,7 @@
 * order_volume_process: [1]      Only log rays that scatter for the n'th time in the same geometry, using the same process
 * logger_conditional_extend_index: [1] If a conditional is used with this logger, the result of each conditional calculation can be made available in extend as a array called "logger_conditional_extend", and one would then acces logger_conditional_extend[n] if logger_conditional_extend_index is set to n
 * init:                 [string] Name of Union_init component (typically "init", default)
+* nowritefile:          [1]      If set, logger will skip writing to disk
 *
 * CALCULATED PARAMETERS:
 *
@@ -77,7 +78,7 @@
 
 DEFINE COMPONENT Union_logger_2D_kf_time
 
-SETTING PARAMETERS(string target_geometry="NULL",string target_process="NULL", Q1_min=-5, Q1_max=5, Q2_min=-5, Q2_max=5, time_min=0, time_max=1,string Q_direction_1="x", string Q_direction_2="z",string filename="NULL", n1=90, n2=90, time_bins=10, order_total=0,order_volume=0,order_volume_process=0,logger_conditional_extend_index=-1, string init="init")
+SETTING PARAMETERS(string target_geometry="NULL",string target_process="NULL", Q1_min=-5, Q1_max=5, Q2_min=-5, Q2_max=5, time_min=0, time_max=1,string Q_direction_1="x", string Q_direction_2="z",string filename="NULL", n1=90, n2=90, time_bins=10, order_total=0,order_volume=0,order_volume_process=0,logger_conditional_extend_index=-1, string init="init", int nowritefile=0)
 
 
 /* Neutron parameters: (x,y,z,vx,vy,vz,t,sx,sy,sz,p) */
@@ -744,14 +745,16 @@ SAVE
 %{
   // Write to disk
 
-  for (loop_index = 0; loop_index < this_storage.Detector_3D.bins_3; loop_index++) {
-    sprintf (number_string, "%d", loop_index);
-    sprintf (part_filename, "%s_%s", this_storage.Detector_3D.Filename, number_string);
+  if (!nowritefile) {
+    for (loop_index = 0; loop_index < this_storage.Detector_3D.bins_3; loop_index++) {
+      sprintf (number_string, "%d", loop_index);
+      sprintf (part_filename, "%s_%s", this_storage.Detector_3D.Filename, number_string);
 
-    DETECTOR_OUT_2D (this_storage.Detector_3D.title_string, this_storage.Detector_3D.string_axis_1, this_storage.Detector_3D.string_axis_2,
-                     this_storage.Detector_3D.D1min, this_storage.Detector_3D.D1max, this_storage.Detector_3D.D2min, this_storage.Detector_3D.D2max,
-                     this_storage.Detector_3D.bins_1, this_storage.Detector_3D.bins_2, &this_storage.Detector_3D.Array_N[loop_index][0][0],
-                     &this_storage.Detector_3D.Array_p[loop_index][0][0], &this_storage.Detector_3D.Array_p2[loop_index][0][0], part_filename);
+      DETECTOR_OUT_2D (this_storage.Detector_3D.title_string, this_storage.Detector_3D.string_axis_1, this_storage.Detector_3D.string_axis_2,
+                       this_storage.Detector_3D.D1min, this_storage.Detector_3D.D1max, this_storage.Detector_3D.D2min, this_storage.Detector_3D.D2max,
+                       this_storage.Detector_3D.bins_1, this_storage.Detector_3D.bins_2, &this_storage.Detector_3D.Array_N[loop_index][0][0],
+                       &this_storage.Detector_3D.Array_p[loop_index][0][0], &this_storage.Detector_3D.Array_p2[loop_index][0][0], part_filename);
+    }
   }
 %}
 
diff --git a/mcstas-comps/union/Union_logger_2D_space.comp b/mcstas-comps/union/Union_logger_2D_space.comp
index b6e6353ae..5ca1c7d43 100644
--- a/mcstas-comps/union/Union_logger_2D_space.comp
+++ b/mcstas-comps/union/Union_logger_2D_space.comp
@@ -62,6 +62,7 @@
 * order_volume_process: [1] Only log rays that scatter for the n'th time in the same geometry, using the same process
 * logger_conditional_extend_index: [1] If a conditional is used with this logger, the result of each conditional calculation can be made available in extend as a array called "logger_conditional_extend", and one would then acces logger_conditional_extend[n] if logger_conditional_extend_index is set to n
 * init:            [string] Name of Union_init component (typically "init", default)
+* nowritefile:     [1]      If set, logger will skip writing to disk
 *
 * CALCULATED PARAMETERS:
 *
@@ -77,7 +78,7 @@ DEFINE COMPONENT Union_logger_2D_space
 SETTING PARAMETERS(string target_geometry="NULL", string target_process="NULL",
                    string D_direction_1="x", D1_min=-5, D1_max=5, n1=90,
                    string D_direction_2="z", D2_min=-5, D2_max=5, n2=90,
-                   string filename="NULL", order_total=0, order_volume=0, order_volume_process=0, logger_conditional_extend_index=-1, string init="init")
+                   string filename="NULL", order_total=0, order_volume=0, order_volume_process=0, logger_conditional_extend_index=-1, string init="init", int nowritefile=0)
 
 
 /* Neutron parameters: (x,y,z,vx,vy,vz,t,sx,sy,sz,p) */
@@ -704,10 +705,12 @@ TRACE
 SAVE
 %{
   // Write to disk
-  DETECTOR_OUT_2D (this_storage.Detector_2D.title_string, this_storage.Detector_2D.string_axis_1, this_storage.Detector_2D.string_axis_2,
-                   this_storage.Detector_2D.D1min, this_storage.Detector_2D.D1max, this_storage.Detector_2D.D2min, this_storage.Detector_2D.D2max,
-                   this_storage.Detector_2D.bins_1, this_storage.Detector_2D.bins_2, *this_storage.Detector_2D.Array_N, *this_storage.Detector_2D.Array_p,
-                   *this_storage.Detector_2D.Array_p2, this_storage.Detector_2D.Filename);
+  if (!nowritefile) {
+    DETECTOR_OUT_2D (this_storage.Detector_2D.title_string, this_storage.Detector_2D.string_axis_1, this_storage.Detector_2D.string_axis_2,
+                     this_storage.Detector_2D.D1min, this_storage.Detector_2D.D1max, this_storage.Detector_2D.D2min, this_storage.Detector_2D.D2max,
+                     this_storage.Detector_2D.bins_1, this_storage.Detector_2D.bins_2, *this_storage.Detector_2D.Array_N, *this_storage.Detector_2D.Array_p,
+                     *this_storage.Detector_2D.Array_p2, this_storage.Detector_2D.Filename);
+  }
 %}
 
 FINALLY
diff --git a/mcstas-comps/union/Union_logger_2D_space_time.comp b/mcstas-comps/union/Union_logger_2D_space_time.comp
index 30186e912..dde39c985 100644
--- a/mcstas-comps/union/Union_logger_2D_space_time.comp
+++ b/mcstas-comps/union/Union_logger_2D_space_time.comp
@@ -65,6 +65,7 @@
 * order_volume_process: [1]      Only log rays that scatter for the n'th time in the same geometry, using the same process
 * logger_conditional_extend_index: [1] If a conditional is used with this logger, the result of each conditional calculation can be made available in extend as a array called "logger_conditional_extend", and one would then acces logger_conditional_extend[n] if logger_conditional_extend_index is set to n
 * init:                 [string] Name of Union_init component (typically "init", default)
+* nowritefile:          [1]      If set, logger will skip writing to disk
 *
 * CALCULATED PARAMETERS:
 *
@@ -77,7 +78,7 @@
 
 DEFINE COMPONENT Union_logger_2D_space_time
 
-SETTING PARAMETERS(string target_geometry="NULL",string target_process="NULL",D1_min=-5,D1_max=5,D2_min=-5,D2_max=5,time_min=0,time_max=1,string D_direction_1="x", string D_direction_2="z",string filename="NULL", n1=90, n2=90, time_bins=10, order_total=0,order_volume=0,order_volume_process=0,logger_conditional_extend_index=-1, string init="init")
+SETTING PARAMETERS(string target_geometry="NULL",string target_process="NULL",D1_min=-5,D1_max=5,D2_min=-5,D2_max=5,time_min=0,time_max=1,string D_direction_1="x", string D_direction_2="z",string filename="NULL", n1=90, n2=90, time_bins=10, order_total=0,order_volume=0,order_volume_process=0,logger_conditional_extend_index=-1, string init="init", int nowritefile=0)
 
 
 /* Neutron parameters: (x,y,z,vx,vy,vz,t,sx,sy,sz,p) */
@@ -767,14 +768,16 @@ SAVE
 %{
   // Write to disk
 
-  for (loop_index = 0; loop_index < this_storage.Detector_3D.bins_3; loop_index++) {
-    sprintf (number_string, "%d", loop_index);
-    sprintf (part_filename, "%s_%s", this_storage.Detector_3D.Filename, number_string);
+  if (!nowritefile) {
+    for (loop_index = 0; loop_index < this_storage.Detector_3D.bins_3; loop_index++) {
+      sprintf (number_string, "%d", loop_index);
+      sprintf (part_filename, "%s_%s", this_storage.Detector_3D.Filename, number_string);
 
-    DETECTOR_OUT_2D (this_storage.Detector_3D.title_string, this_storage.Detector_3D.string_axis_1, this_storage.Detector_3D.string_axis_2,
-                     this_storage.Detector_3D.D1min, this_storage.Detector_3D.D1max, this_storage.Detector_3D.D2min, this_storage.Detector_3D.D2max,
-                     this_storage.Detector_3D.bins_1, this_storage.Detector_3D.bins_2, &this_storage.Detector_3D.Array_N[loop_index][0][0],
-                     &this_storage.Detector_3D.Array_p[loop_index][0][0], &this_storage.Detector_3D.Array_p2[loop_index][0][0], part_filename);
+      DETECTOR_OUT_2D (this_storage.Detector_3D.title_string, this_storage.Detector_3D.string_axis_1, this_storage.Detector_3D.string_axis_2,
+                       this_storage.Detector_3D.D1min, this_storage.Detector_3D.D1max, this_storage.Detector_3D.D2min, this_storage.Detector_3D.D2max,
+                       this_storage.Detector_3D.bins_1, this_storage.Detector_3D.bins_2, &this_storage.Detector_3D.Array_N[loop_index][0][0],
+                       &this_storage.Detector_3D.Array_p[loop_index][0][0], &this_storage.Detector_3D.Array_p2[loop_index][0][0], part_filename);
+    }
   }
 %}
 
diff --git a/mcstas-comps/union/Union_logger_3D_space.comp b/mcstas-comps/union/Union_logger_3D_space.comp
index cc6980e42..96b5e6821 100644
--- a/mcstas-comps/union/Union_logger_3D_space.comp
+++ b/mcstas-comps/union/Union_logger_3D_space.comp
@@ -67,6 +67,7 @@
 * order_volume_process: [1] Only log rays that scatter for the n'th time in the same geometry, using the same process
 * logger_conditional_extend_index: [1] If a conditional is used with this logger, the result of each conditional calculation can be made available in extend as a array called "logger_conditional_extend", and one would then acces logger_conditional_extend[n] if logger_conditional_extend_index is set to n
 * init:                 [string] name of Union_init component (typically "init", default)
+* nowritefile:          [1]      If set, logger will skip writing to disk
 *
 * CALCULATED PARAMETERS:
 *
@@ -79,7 +80,7 @@
 
 DEFINE COMPONENT Union_logger_3D_space
 
-SETTING PARAMETERS(string target_geometry="NULL",string target_process="NULL",D1_min=-1,D1_max=1,D2_min=-1,D2_max=1,D3_min=-1,D3_max=1,string D_direction_1="x", string D_direction_2="z", string D_direction_3="z",string filename="NULL", n1=90, n2=90, n3=10,  order_total=0,order_volume=0,order_volume_process=0,logger_conditional_extend_index=-1, string init="init")
+SETTING PARAMETERS(string target_geometry="NULL",string target_process="NULL",D1_min=-1,D1_max=1,D2_min=-1,D2_max=1,D3_min=-1,D3_max=1,string D_direction_1="x", string D_direction_2="z", string D_direction_3="z",string filename="NULL", n1=90, n2=90, n3=10,  order_total=0,order_volume=0,order_volume_process=0,logger_conditional_extend_index=-1, string init="init", int nowritefile=0)
 
 
 /* Neutron parameters: (x,y,z,vx,vy,vz,t,sx,sy,sz,p) */
@@ -828,14 +829,16 @@ SAVE
 %{
   // Write to disk
 
-  for (loop_index = 0; loop_index < this_storage.Detector_3D.bins_3; loop_index++) {
-    sprintf (number_string, "%d", loop_index);
-    sprintf (part_filename, "%s_%s", this_storage.Detector_3D.Filename, number_string);
+  if (!nowritefile) {
+    for (loop_index = 0; loop_index < this_storage.Detector_3D.bins_3; loop_index++) {
+      sprintf (number_string, "%d", loop_index);
+      sprintf (part_filename, "%s_%s", this_storage.Detector_3D.Filename, number_string);
 
-    DETECTOR_OUT_2D (this_storage.Detector_3D.title_string, this_storage.Detector_3D.string_axis_1, this_storage.Detector_3D.string_axis_2,
-                     this_storage.Detector_3D.D1min, this_storage.Detector_3D.D1max, this_storage.Detector_3D.D2min, this_storage.Detector_3D.D2max,
-                     this_storage.Detector_3D.bins_1, this_storage.Detector_3D.bins_2, &this_storage.Detector_3D.Array_N[loop_index][0][0],
-                     &this_storage.Detector_3D.Array_p[loop_index][0][0], &this_storage.Detector_3D.Array_p2[loop_index][0][0], part_filename);
+      DETECTOR_OUT_2D (this_storage.Detector_3D.title_string, this_storage.Detector_3D.string_axis_1, this_storage.Detector_3D.string_axis_2,
+                       this_storage.Detector_3D.D1min, this_storage.Detector_3D.D1max, this_storage.Detector_3D.D2min, this_storage.Detector_3D.D2max,
+                       this_storage.Detector_3D.bins_1, this_storage.Detector_3D.bins_2, &this_storage.Detector_3D.Array_N[loop_index][0][0],
+                       &this_storage.Detector_3D.Array_p[loop_index][0][0], &this_storage.Detector_3D.Array_p2[loop_index][0][0], part_filename);
+    }
   }
 %}