diff --git a/gripper_dev/gripper_dev/gripper_dev_node.py b/gripper_dev/gripper_dev/gripper_dev_node.py
index be208a4..7f1f728 100644
--- a/gripper_dev/gripper_dev/gripper_dev_node.py
+++ b/gripper_dev/gripper_dev/gripper_dev_node.py
@@ -36,6 +36,14 @@ class GripperDevNode(Node):
         self.cur_goal=None
         self.timer_on=False
         self.target_mode=0
+        self.enable_ok=False
+        flag = self.clawControl.serialOperation(self.com_dev, 115200, True)
+        if flag==1:
+            ret = self.clawControl.enableClamp(self.devid, True)
+            if ret==1:
+                self.enable_ok=True
+            else:
+                print(self.comd_dev,'enble fail!')
         print('gripper_dev_node init:',self.com_dev)
         #self.feedback_timer = self.create_timer(0.1, self.update_feedback) 
     def gripper_cmd_callback_action(self,goal):
@@ -46,20 +54,22 @@ class GripperDevNode(Node):
         self.target_torque=req.torque
         self.target_mode=req.mode
         print('recv goal',self.devid,self.target_loc,self.target_speed,self.target_torque,self.target_mode)
-        flag = self.clawControl.serialOperation(self.com_dev, 115200, True)
-        if flag==1:
-            ret = self.clawControl.enableClamp(self.devid, True)
-            if ret!=1:
-                print('enble fail!')
-                result=GripperCmd.Result()
-                result.state="gripper enable fail!"
-                result.result=0
-                goal.abort()
-                return result
-            print('start run...')
+        #flag = self.clawControl.serialOperation(self.com_dev, 115200, True)
+        #if flag==1:
+        #    ret = self.clawControl.enableClamp(self.devid, True)
+        #    if ret!=1:
+        #        print('enble fail!')
+        #        result=GripperCmd.Result()
+        #        result.state="gripper enable fail!"
+        #        result.result=0
+        #        goal.abort()
+        #        return result
+        #    print('start run...')
+        if self.enable_ok:
             self.clawControl.runWithParam(self.devid,self.target_loc,self.target_speed,self.target_torque)
             ##feedback
             loop_flag=True
+            loop_times=0
             while loop_flag:
                 loc = self.clawControl.getClampCurrentLocation(self.devid)
                 speed = self.clawControl.getClampCurrentSpeed(self.devid)
@@ -80,9 +90,18 @@ class GripperDevNode(Node):
                 print('update feedback:',feedback_msg)
                 self.cur_goal.publish_feedback(feedback_msg)
                 time.sleep(1)
+                loop_times+=1
+                if loop_times>15:
+                    result=GripperCmd.Result()
+                    result.state="loop timeout!!!"
+                    result.result=0
+                    goal.abort()
+                    loop_times=0
+                    return result
+
         else:
             result=GripperCmd.Result()
-            result.state="uart open fail!"
+            result.state="uart open fail & enable fail!"
             result.result=0
             goal.abort()
             return result
@@ -96,7 +115,10 @@ class GripperDevNode(Node):
         goal.succeed()
         print('action finish',state)
         return result
-        
+    def destroy_node(self):
+        super.destroy_node()
+        flag = self.clawControl.serialOperation(self.com_dev, 115200, False)
+
     def gripper_cmd_callback(self, request, response):
         self.cur_loc=request.loc
         self.cur_speed=request.speed
@@ -116,6 +138,7 @@ def main():
     rclpy.init()
     node=GripperDevNode()
     rclpy.spin(node)
+    node.destroy_node()
     rclpy.shutdown()
     pass
 if __name__ == '__main__':