Index: firmware/App/Modes/ModePreTreat.c
===================================================================
diff -u -r809d8fc395e63afc52a13fc30087d2cf50ad4d9a -r3eab17f4bf956168bd11eb0a54c2dce66b54946a
--- firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision 809d8fc395e63afc52a13fc30087d2cf50ad4d9a)
+++ firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision 3eab17f4bf956168bd11eb0a54c2dce66b54946a)
@@ -16,6 +16,7 @@
 ***************************************************************************/
 
 #include "AlarmMgmt.h"
+#include "Buttons.h"
 #include "ConsumableSelfTest.h"
 #include "FPGA.h"
 #include "ModePreTreat.h"
@@ -152,6 +153,13 @@
 *************************************************************************/
 U32 execPreTreatmentMode( void )
 {
+    BOOL stop = isStopButtonPressed();
+
+    if ( TRUE == stop )
+    {
+        activateAlarmNoData( ALARM_ID_TREATMENT_STOPPED_BY_USER );
+    }
+
     // execute mode state machine
     switch ( currentPreTreatmentState )
     {