diff --git a/DSO138mini_data.py b/DSO138mini_data.py
index 20b9e66..af23dbb 100644
--- a/DSO138mini_data.py
+++ b/DSO138mini_data.py
@@ -10,35 +10,58 @@
     TODO: Format plot with parameters.
 '''
 
-if (len(sys.argv) == 1 or sys.argv[1] == "-h" or sys.argv[1] == "--help"):
-    print("Usage: python DSO138mini.py [COM port] [baud rate] [output file]")
+if len(sys.argv) != 2 and len(sys.argv) != 4:
+    print("Invalid number of arguments. Use -h or --help for more information.")
+    sys.exit()
+# setting up the arguments
+if (sys.argv[1] == "-h" or sys.argv[1] == "--help"):
+    print(
+        "Usage: python DSO138mini.py [COM port] [baudrate (default=15200)] [output file]")
     print("Example: python DSO138mini.py COM3 115200 data.txt")
     sys.exit()
 
-if len(sys.argv) != 4:
-    print("Invalid number of arguments. Use -h or --help for more information.")
+if sys.platform == "linux" or sys.platform == "linux2":
+    COM = "/dev/tty" + sys.argv[1]
+elif sys.platform == "win32":
+    COM = sys.argv[1] if sys.argv[1].startswith("COM") else "COM" + sys.argv[1]
+else:
+    print("Unsupported platform")
     sys.exit()
 
-COM = sys.argv[1] if sys.argv[1].startswith("COM") else "COM" + sys.argv[1]
+# setting up the parameters
 BAUD = int(sys.argv[2]) if sys.argv[2].isnumeric() else 115200
-filename = sys.argv[3] if sys.argv[3].endswith(
-    ".txt") else sys.argv[3] + ".txt"
-save_file_param = open(filename+"_param.json", "w")
-save_file_data = open(filename+"_data.json", "w")
+FILENAME = sys.argv[3]
 
 
 class DSO138mini:
-    def __init__(self, COM, BAUD, FILENAME="data.txt"):
+    def __init__(self, COM, BAUD, FILENAME="DSO138"):
         self.COM = COM
         self.BAUD = BAUD
         self.FILENAME = FILENAME
 
     def connect(self):
-        self.ser = serial.Serial(port=self.COM, baudrate=self.BAUD, timeout=2)
+
+        # initialize serial connection
+        try:
+            self.ser = serial.Serial(
+                port=self.COM, baudrate=self.BAUD, timeout=1)
+        except serial.SerialException:
+            print(f"Faild to open {COM} . Exiting...")
+            sys.exit()
+        except KeyboardInterrupt:
+            print("Interrupted by User, Exiting...")
+            sys.exit()
+
+        if (self.ser.is_open):
+            print("Connected to " + self.COM)
 
     def save_data(self):
-        count = 0
-        oci_para = {}
+        # open files
+        save_file_param = open(self.FILENAME + "_param.json", "w")
+        save_file_data = open(self.FILENAME + "_data.json", "w")
+        count = 0  # counter for lines DSO138 sends 1043 lines of data
+        oci_para = {}  # firtst 19 lines are parameters
+        # rest of the data is plot data (1023 lines) 3 columns (seq, time, voltage)
         plot_data = []
         try:
             while True:
@@ -61,18 +84,23 @@ def save_data(self):
                         break
                     print(data, flush=True)
                 else:
-                    print("waiting for data...", end="\r", flush=True)
+                    print("waiting for data...", end="\r")
+
         except KeyboardInterrupt:
             self.ser.close()
             json.dump(oci_para, save_file_param)
             json.dump(plot_data, save_file_data)
             save_file_data.close()
             save_file_param.close()
-            print("Data saved to " + filename)
+            print("Data saved to " + self.FILENAME)
             sys.exit()
-
+        except serial.SerialException:
+            print("Serial connection lost. Exiting...")
+            sys.exit()
+            
         return oci_para, plot_data
 
+    # TODO: Format plot with parameters.
     def plot_data(self, plot_data, oci_para):
         plot_data = np.array(plot_data)
         plt.plot(plot_data[:, 1], plot_data[:, 2])
@@ -91,10 +119,10 @@ def plot_data(self, plot_data, oci_para):
 
 
 def main():
-    dso = DSO138mini(COM, BAUD, filename)
+    dso = DSO138mini(COM, BAUD, FILENAME)
     dso.connect()
     oci_para, plot_data = dso.save_data()
-    print("Data saved to " + filename)
+    print("Data saved to " + FILENAME)
     # dso.plot_data(plot_data, oci_para)
     return oci_para, plot_data