diff --git a/__init__.py b/__init__.py
index aed3eec..34203e5 100644
--- a/__init__.py
+++ b/__init__.py
@@ -53,6 +53,7 @@ class tcp_base(object):
     LOG_PREFIX = 'TCP_IP:'
     RX_LENGTH = 0xff
     COM_TIMEOUT = 0.5
+    IS_CLIENT = False
 
     def __init__(self, host, port, rx_log_lvl=logging.INFO):
         self.host = host
@@ -289,6 +290,8 @@ class tcp_client(tcp_base):
 
     .. literalinclude:: ../../tcp_socket/_examples_/tcp_socket__tcp_client.log
     """
+    IS_CLIENT = True
+
     def __connect__(self):
         if self.__socket__ is None:
             # Create a TCP/IP socket