TCP伺服器端和用戶端建立連接配接 - 用戶端的回調處理

使用異步操作client.connect發起連接配接，

async function startClient(ip = configJson.TCP.client.ip, port = configJson.TCP.client.port) {
    client = new net.Socket();
    await client.connect(port, ip, () => {
      console.log(" in tcpclient.js connect callback!!! await function");
    });      

client.on('connect', (dataTmp) => {
        log.info('Congratulations! Statemachine is connected(in callback)');
    // send message to TCP server, method: subscribe, data: { group: "statemachine"} 
            TCPClient.sendMessage(message.message({group: "statemachine"},'subscribe'));
    })