TCPIPclientTest.rst

TCPIPclientTest.py

You can view and download this file on Github: TCPIPclientTest.py

#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
# This is an EXUDYN example
#
# Details:  Example for connecting two Python codes via TCP/IP
#           See file TCPIPserverTest.py for running on the other Python instance
#
# Author:   Johannes Gerstmayr
# Date:     2021-11-06
#
# Copyright:This file is part of Exudyn. Exudyn is free software. You can redistribute it and/or modify it under the terms of the Exudyn license. See 'LICENSE.txt' for more details.
#
#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++


import socket
import sys
import time
import struct
packer = struct.Struct('I d d d d')
ackPacker = struct.Struct('I')

HOST='127.0.0.1'
PORT = 65124
# Create a TCP/IP socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

# Connect the socket to the port where the server is listening
server_address = (HOST, PORT)
print('connecting to %s port %s' % server_address)
sock.connect(server_address)
# After the connection is established, data can be sent through the socket with sendall() and received with recv(), just as in the server.


t = 0
try:

    # Send data
    # message = 'This is the message.  It will be repeated.'
    # print('sending "%s"' % message)
    # byteMessage=message.encode(encoding='utf-8')
    # sock.sendall(byteMessage)

    while t < 10:
        x=1.13
        y=4
        z=-3.1415
        values = (4, t, x, y, z)
        byteMessage = packer.pack(*values)
        print("send", values)
        sock.sendall(byteMessage)
        chksum = sum(byteMessage)
        ackData = ackPacker.pack(chksum)

        ackReceived = False
        timeout = 0
        while not ackReceived:
            data = sock.recv(len(ackData)) #recv waits until it receives the package!
            # if (len(data)):
            #     print(data, len(data), ackPacker.unpack(data)[0] ,'==', chksum)
            if len(data) == len(ackData) and ackPacker.unpack(data)[0] == chksum:
                print('  ok (', ackPacker.unpack(data)[0], ')')
                ackReceived = True
            else:
                print('error in checksum; check your connection')
                ackReceived = True

        time.sleep(0.5)
        t+=0.5

        # Look for the response
        # amount_received = 0
        # amount_expected = len(byteMessage)

        # while amount_received < amount_expected:
        #     data = sock.recv(16)
        #     amount_received += len(data)
        #     print('received "%s"' % data)

finally:
    print('closing socket')
    sock.close()