diff --git a/APP/inc/rtconfig.h b/APP/inc/rtconfig.h
index 8cf88c3..03aaf38 100644
--- a/APP/inc/rtconfig.h
+++ b/APP/inc/rtconfig.h
@@ -25,7 +25,7 @@
 #define RT_USING_HOOK
 
 /* Using Software Timer */
-/* #define RT_USING_TIMER_SOFT */
+#define RT_USING_TIMER_SOFT
 #define RT_TIMER_THREAD_PRIO		4
 #define RT_TIMER_THREAD_STACK_SIZE	512
 #define RT_TIMER_TICK_PER_SECOND	1000
diff --git a/FreeModbus/port/rtt/portserial.c b/FreeModbus/port/rtt/portserial.c
index a97841f..6f8e71d 100644
--- a/FreeModbus/port/rtt/portserial.c
+++ b/FreeModbus/port/rtt/portserial.c
@@ -107,6 +107,7 @@ BOOL xMBPortSerialInit(UCHAR ucPORT, ULONG ulBaudRate, UCHAR ucDataBits,
     }
 
     /* software initialize */
+    rt_event_init(&event_serial, "slave event", RT_IPC_FLAG_PRIO);
     rt_thread_init(&thread_serial_soft_trans_irq,
                    "slave trans",
                    serial_soft_trans_irq,
@@ -115,7 +116,6 @@ BOOL xMBPortSerialInit(UCHAR ucPORT, ULONG ulBaudRate, UCHAR ucDataBits,
                    sizeof(serial_soft_trans_irq_stack),
                    10, 5);
     rt_thread_startup(&thread_serial_soft_trans_irq);
-    rt_event_init(&event_serial, "slave event", RT_IPC_FLAG_PRIO);
 
     return TRUE;
 }
diff --git a/FreeModbus/port/rtt/portserial_m.c b/FreeModbus/port/rtt/portserial_m.c
index 93a4af7..d19750c 100644
--- a/FreeModbus/port/rtt/portserial_m.c
+++ b/FreeModbus/port/rtt/portserial_m.c
@@ -108,6 +108,7 @@ BOOL xMBMasterPortSerialInit(UCHAR ucPORT, ULONG ulBaudRate, UCHAR ucDataBits,
     }
 
     /* software initialize */
+    rt_event_init(&event_serial, "master event", RT_IPC_FLAG_PRIO);
     rt_thread_init(&thread_serial_soft_trans_irq,
                    "master trans",
                    serial_soft_trans_irq,
@@ -116,7 +117,6 @@ BOOL xMBMasterPortSerialInit(UCHAR ucPORT, ULONG ulBaudRate, UCHAR ucDataBits,
                    sizeof(serial_soft_trans_irq_stack),
                    10, 5);
     rt_thread_startup(&thread_serial_soft_trans_irq);
-    rt_event_init(&event_serial, "master event", RT_IPC_FLAG_PRIO);
 
     return TRUE;
 }
diff --git a/FreeModbus/port/rtt/porttimer.c b/FreeModbus/port/rtt/porttimer.c
index 6f017d8..8c51ad0 100644
--- a/FreeModbus/port/rtt/porttimer.c
+++ b/FreeModbus/port/rtt/porttimer.c
@@ -37,7 +37,7 @@ BOOL xMBPortTimersInit(USHORT usTim1Timerout50us)
     rt_timer_init(&timer, "slave timer",
                    timer_timeout_ind, /* bind timeout callback function */
                    RT_NULL,
-                   (50*usTim1Timerout50us)/(1000*1000/RT_TICK_PER_SECOND),
+                   (50 * usTim1Timerout50us) / (1000 * 1000 / RT_TICK_PER_SECOND) + 1,
                    RT_TIMER_FLAG_ONE_SHOT); /* one shot */
     return TRUE;
 }
diff --git a/FreeModbus/port/rtt/porttimer_m.c b/FreeModbus/port/rtt/porttimer_m.c
index 00441bf..ebf8000 100644
--- a/FreeModbus/port/rtt/porttimer_m.c
+++ b/FreeModbus/port/rtt/porttimer_m.c
@@ -46,7 +46,7 @@ BOOL xMBMasterPortTimersInit(USHORT usTimeOut50us)
     rt_timer_init(&timer, "master timer",
                    timer_timeout_ind, /* bind timeout callback function */
                    RT_NULL,
-                   (50 * usT35TimeOut50us) / (1000 * 1000 / RT_TICK_PER_SECOND),
+                   (50 * usT35TimeOut50us) / (1000 * 1000 / RT_TICK_PER_SECOND) + 1,
                    RT_TIMER_FLAG_ONE_SHOT); /* one shot */
 
     return TRUE;