套接字已被第三方断开连接

Question

我想通过节点js客户端连接opc-ua服务器。但是我收到错误消息，例如套接字已被第三方断开连接 在ClientTCP_transport.TCP_transport._on_socket_ended_message（/home/samit/node-project/node_modules/node-opcua-transport/src/tcp_transport.js:267:18）

var opcua = require("node-opcua");
var async = require("async");
var client = new opcua.OPCUAClient();
var endpointUrl = "opc.tcp://localhost:62541";
var the_session, the_subscription;

    async.series([
        function(callback)  {
            client.connect(endpointUrl,function (err) {
                if(err) {
                    console.log(" cannot connect to endpoint :", endpointUrl );
                } else {
                    console.log("connected !");
                }
                callback(err);
            });


        }
    ],
    function(err) {
        if (err) {
            console.log(" failure ",err);
        } else {
            console.log("done!");
        }
        client.disconnect(function(){});
    }) ;