Read data sent over TCP from the Python script to the browser via socket.io on the Node server. Problems occur when I open my browser to localhost:8081 and the terminal fills with a bunch of random numbers and the page loads incredibly slow, and the browser doesn't seem to receive any data.

client.js

min_graph = 0;
max_graph = 0;
options = {
  series: { shadowSize: 0 }, // drawing is faster without shadows
  xaxis: { show: false },
  legend: { show: true }
};

$(function () {
    var lowV = 1000;
    var lowS = 1000;
    var maxPoints = 5 * 50;
    var dataSetpoint = [];
    var dataValue = [];
    var dataControl = [];
    lowest = 1000000;
    highest = 0;
    function getData() {
      var resS = [];
      var resV = [];
      var resC = [];
      var min = 0;
      var max = 0;

      for (var i = 0; i < maxPoints; ++i)
         if( i > dataSetpoint.length)
           resS.push([i, 0]);
         else {
           resS.push([i, dataSetpoint[i]]);
           min = (dataSetpoint[i] < min) ? dataSetpoint[i] : min;
           max = (dataSetpoint[i] > max) ? dataSetpoint[i] : max;
         }
      for (var i = 0; i < maxPoints; ++i)
         if( i > dataValue.length)
           resV.push([i, 0]);
         else {
           resV.push([i, dataValue[i]]);
           min = (dataValue[i] < min) ? dataValue[i] : min;
           max = (dataValue[i] > max) ? dataValue[i] : max;
         }

      for (var i = 0; i < maxPoints; ++i)
         if( i > dataControl.length)
           resC.push([i, 0]);
         else {
           resC.push([i, dataControl[i]]);
           min = (dataControl[i] < min) ? dataControl[i] : min;
           max = (dataControl[i] > max) ? dataControl[i] : max;
         }
      min_graph = min;
      max_graph = max;

      var res = [{label: "S", data: resS},
                 {label: "V", data: resV},
                 {label: "C", data: resC}]; //console.log(res);
      return res;
    }
    // setup plot


    function makeplot() {
      $('#pid_plot').css('width', function(index) {
         return $(window).width() * .9;
      });
      $('#pid_plot').css('height', function(index) {
          return $(window).height() * .8;
      });
      plot = $.plot($("#pid_plot"), getData(), options);
    }
    makeplot();
    $(window).resize(makeplot);

    function push(newS, newV, newC) {
      var min;
      if (dataSetpoint.length > 0)
          dataSetpoint = dataSetpoint.slice(1);

      if (newS < lowest) {
          lowest = newS;
      }
      if (newS > highest) {
          highest = newS;
      }
      while (dataSetpoint.length < maxPoints) {
          var y = newS;
          dataSetpoint.push(y);
      }

      if (dataValue.length > 0)
          dataValue = dataValue.slice(1);

      while (dataValue.length < maxPoints) {
          var y = newV;
          dataValue.push(y);
      }

      if (dataControl.length > 0)
          dataControl = dataControl.slice(1);

      while (dataControl.length < maxPoints) {
          //var y = (newC * ((max_graph-5 - (min_graph+5))/2)) + ((max_graph-5 - (min_graph+5))/2) ;
          var y = newC;
           dataControl.push(y);
      }

      plot.setupGrid();
      plot.setData(getData());
      plot.draw();
    }

    var socket = io.connect('http://localhost');
    socket.on('update', function (dataIn) {
      push(dataIn["S"], dataIn["V"],dataIn["C"]);
      console.log(dataIn);
    });

});

tcp_server.js

var express = require("express");
var net = require("net");
var app = require("express");
var server = require('http').createServer(app).listen(8081);
var io = require('socket.io').listen(server);

var HTTP_PORT = 8081;
var TCP_PORT = 41234;

//app.listen(HTTP_PORT);
express.use("/js", express.static(__dirname + '/js'));
express.use("/css", express.static(__dirname + '/css'));
express.use("/images", express.static(__dirname + '/images'));
express.get('/', function (req, res) {
  res.sendfile(__dirname + '/index.html');
});

var clients = [];
net.createServer(function (socket) {

  // Identify the client
  socket.name = socket.remoteAddress + ":" + socket.remotePort

  // Put this new client in the list
  clients.push(socket);

  broadcast(socket.name + " connected", socket);

  // Handle incoming messages from clients.
  socket.on('data', function (data) {
    broadcast(data, socket);
  });

  // Remove the client from the list when it leaves
  socket.on('end', function () {
    clients.splice(clients.indexOf(socket), 1);
    //broadcast(socket.name + " disconnected.");
  });

  // Send a message to all clients
  function broadcast(message, sender) {
    io.sockets.emit('update', message);
    console.log(message.toString("utf8"));
  }

}).listen(TCP_PORT);

// Put a friendly message on the terminal of the server.
console.log("Listening...");

tcp_tester.py

import time
import math
import socket

TCP_IP = "127.0.0.1"
TCP_PORT = 41234
SLEEP_INTERVAL = 1

HOST, PORT = TCP_IP, TCP_PORT

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((HOST, PORT))

i = 0
while True:
    try:
        while True:
            msg='{"S":%d, "V":%d, "C":%d}' % (((math.sin(i) + 1) *50), ((math.cos(i) + 1) * 50), (math.cos(i)))
            sock.sendall(msg + "|")
            print "Sent:\t{}".format(msg)
            time.sleep(SLEEP_INTERVAL)
            i += .1
    finally:
        sock.close()