FirstScan plc fo implemented

src/lib/rt/src/rt_plc.h

@@ -145,6 +145,7 @@ struct plc_sThread {
 
   plc_sArea		copy;
   io_tCtx		plc_io_ctx;
+  pwr_tBoolean		first_scan;
 };
 
 struct plc_sProcess {

src/lib/rt/src/rt_plc_thread.c

@@ -228,6 +228,9 @@ scan (
     }
   }
 
+  if ( tp->first_scan)
+    tp->first_scan = 0;
+
   time_Uptime(&sts, &tp->after_scan, NULL);
   if (sts == TIME__CLKCHANGE) {
     tp->after_scan = tp->before_scan;