diff --git a/CHANGELOG.md b/CHANGELOG.md
index 55a11b2..c4ea7d2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,11 @@
 # ChangeLog for pymycobot
 
-## v2.7.2.1 (2021-12-15)
+## v2.7.4 (2021-12-15)
+
+- release v2.7.4
+- Fix m5 network communication bug
+
+## v2.7.3 (2021-12-15)
 
 - release v2.7.3
 - fix get_tof_distance() no return problem.
diff --git a/docs/README.md b/docs/README.md
index 807621c..d58f3e5 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -80,7 +80,7 @@ We support Python2, Python3.5 or later.
 - [utils (Module)](#utils-module)
   - [get_port_list](#get_port_list)
   - [detect_port_of_basic](#detect_port_of_basic)
-  - [MyCobotSocket](#mycobotsocket)
+- [MyCobotSocket](#mycobotsocket)
     - [Client](#client)
     - [Server](#server)
   - [socket control](#socket-control)
@@ -89,6 +89,7 @@ We support Python2, Python3.5 or later.
     - [set_gpio_out](#set_gpio_out)
     - [set_gpio_output](#set_gpio_output)
     - [get_gpio_in](#get_gpio_in)
+  
 
 <!-- vim-markdown-toc -->
 </details>
@@ -788,10 +789,10 @@ from pymycobot import utils
   mycobot = MyCobot(port, 115200)
   ```
 
-## MyCobotSocket
+# MyCobotSocket
 
 > Note:
-> Only supports python3
+> raspberryPi version Only supports python3
 > The robotic arm that uses this class of premise has a server and has been turned on.
 
 Use TCP/IP to control the robotic arm
diff --git a/pymycobot/__init__.py b/pymycobot/__init__.py
index 15e7152..1491b21 100644
--- a/pymycobot/__init__.py
+++ b/pymycobot/__init__.py
@@ -20,7 +20,7 @@
     "MyCobotSocket"
 ]
 
-__version__ = "2.7.3"
+__version__ = "2.7.4"
 __author__ = "Elephantrobotics"
 __email__ = "weiquan.xu@elephantrobotics.com"
 __git_url__ = "https://github.com/elephantrobotics/pymycobot"
diff --git a/pymycobot/common.py b/pymycobot/common.py
index 3155b3a..57facbb 100644
--- a/pymycobot/common.py
+++ b/pymycobot/common.py
@@ -196,23 +196,31 @@ def _process_single(self, data):
 
 def write(self, command, method=None):
     if method == "socket":
-        if command[3] == 176 and len(command) > 5:
+        data = b""
+        if len(command)>3 and command[3] == 176 and len(command) > 5:
             command = "'"+command[4]+"'"+"("+command[5]+")"
             command = command.encode()
-        self.sock.sendall(bytes(command))
-        if command[-2] == 177:
+        if self.rasp:
+            self.sock.sendall(str(command).encode())
+        else:
+            self.sock.sendall(bytes(command))
+        
+        if len(command) > 3 and command[3] == 177:
             while True:
                 data = self.sock.recv(1024)
                 if b'password' in data:
                     break
-        if command[-2] == 192:
-            data = b''
+        elif len(command) > 3 and command[3] == 192:
             while True:
                 data += self.sock.recv(1024)
                 if len(data) == 6:
                     break
         else:
-            data = self.sock.recv(1024)
+            try:
+                self.sock.settimeout(0.1)
+                data = self.sock.recv(1024)
+            except:
+                data = b''
         return data
     else:
         self.log.debug("_write: {}".format(command))
diff --git a/pymycobot/mycobotsocket.py b/pymycobot/mycobotsocket.py
index 5e9c6cd..7a36da1 100644
--- a/pymycobot/mycobotsocket.py
+++ b/pymycobot/mycobotsocket.py
@@ -58,9 +58,18 @@ def __init__(self, ip, netport=9000):
         self.calibration_parameters = calibration_parameters
         self.SERVER_IP = ip
         self.SERVER_PORT = netport
+        self.rasp = False
         self.sock = self.connect_socket()
 
     def connect(self, serialport="/dev/ttyAMA0", baudrate="1000000", timeout='0.1'):
+        """Interface to connect to the built-in system such as Raspberry Pi
+        Args:
+            serialport: 
+            baudrate: 
+            timeout:
+        
+        """
+        self.rasp = True
         self._write(serialport, "socket")
         self._write(baudrate, "socket")
         self._write(timeout, "socket")
@@ -86,7 +95,7 @@ def _mesg(self, genre, *args, **kwargs):
             MyCobotSocket, self)._mesg(genre, *args, **kwargs)
         # [254,...,255]
         data = self._write(self._flatten(real_command), "socket")
-        if data != b'None':
+        if data:
             res = self._process_received(data, genre)
             if genre in [
                 ProtocolCode.IS_POWER_ON,