Running an echo server as a daemon process for testing in python

I want to automate testing of an instrument and wrote a little server program to imitate the instrument which will send back the command except when it receives a special command "*IDN?". When I ran the echo server directly in its own script, and then run a client script separately, everything works great, and I am getting back the expected results. Now I wanted to run the server directly from the testing script. So I thought I would start it using multiprocessing. But the problem seems to be when the server socket gets to the s.accept() line it just waits there and never returns. So how do I accomplish automated testing if I cannot run this server in the same code as the test function?

import socket
import multiprocessing as mp
import time,sys

HOST = '127.0.0.1'  # Standard loopback interface address (localhost),
PORT = 65432        # Port to listen on (non-privileged ports are > 1023),
FTP_PORT = 63217    # Port for ftp testing, change to 21 for device

def handle_connection(conn,addr):
    with conn:
        conn.send('Connected by', addr)
        print("Got connection")
        data = conn.recv(1024)
        if not data:
            return 'Nodata'
        elif (data == b'*IDN?\n'):
            print('SONY/TEK,AWG520,0,SCPI:95.0 OS:3.0 USR:4.0\n')
            conn.sendall(b'SONY/TEK,AWG520,0,SCPI:95.0 OS:3.0 USR:4.0\n')
            return 'IDN'
        else:
            conn.sendall(data)
            return 'Data'


def echo_server(c_conn,host=HOST,port=PORT):
    # this server simulates the AWG command protocol, simply echoing the command back except for IDN?
    p = mp.current_process()
    print('Starting echo server:', p.name, p.pid)
    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
        s.bind((host, port))
        s.listen()
        try:
            while True:
                print("Waiting for connection...")
                c_conn.send('waiting for connection...')
                conn, addr = s.accept()
                handle_connection(conn,addr)
                c_conn.send('serving client...')
        finally:
            conn.close()
            c_conn.send('done')
            time.sleep(2)
            print('Exiting echo server:', p.name, p.pid)
            sys.stdout.flush()



def test_echo_server():
    print("entering client part")
    with socket.socket(socket.AF_INET,socket.SOCK_STREAM) as mysock:
        mysock.connect((HOST,PORT))
        mysock.sendall('test\n'.encode())
        data = mysock.recv(1024)
    print('received:',repr(data))


if __name__ == '__main__':
    parent_conn, child_conn = mp.Pipe()
    echo_demon = mp.Process(name='echo', target=echo_server(child_conn, ))
    echo_demon.daemon = True
    echo_demon.start()
    time.sleep(1)
    echo_demon.join(1)
    test_echo_server()
    if parent_conn.poll(1):
        print(parent_conn.recv())
    else:
        print('Waiting for echo server')