--- a/lib/iec_std_lib.h	Fri Oct 05 17:58:44 2007 +0200
+++ b/lib/iec_std_lib.h	Wed Oct 17 17:51:24 2007 +0200
@@ -179,8 +179,20 @@
     DATE    DATEvar;
 } __IL_DEFVAR_T;
 
-
-
+typedef struct {
+  char state;     // current step state. 0 : inative, 1: active
+  char prev_state;  // previous step state. 0 : inative, 1: active
+  TIME elapsed_time;  // time since step is active
+} STEP;
+
+typedef struct {
+  char stored;  // action storing state. 0 : not stored, 1: stored
+  char state; // current action state. 0 : inative, 1: active
+  char set;   // set have been requested (reset each time the body is evaluated)
+  char reset; // reset have been requested (reset each time the body is evaluated)
+  TIME set_remaining_time;    // time before set will be requested
+  TIME reset_remaining_time;  // time before reset will be requested
+} ACTION;
 
 /*****************/
 /* Misc internal */