io.sockets.on( "connection", function( socket ){
	console.log('socket connect');
	let client = modbus.client.tcp.complete({ 
        'host'              : '192.168.1.8', 
        'port'              : 10000,
        'autoReconnect'     : false,
        'reconnectTimeout'  : 1000,
        'timeout'           : 5000,
        'unitId'            : 1
	});
	client.connect();
	client.on('connect', function () {
		console.log('modbus');
		setInterval(function(){
			client.readInputRegisters(1,24).then(function(resp){
					let arr=resp.payload;
					socket.emit('info',arr);
				},console.error);
		},1000);
		socket.on('switch',function(msg){
			console.log(msg.flag+" "+msg.on);
			client.writeSingleCoil(msg.flag, msg.on).then(function (resp) {
				console.log(resp);
			}, console.error);
			console.log(msg);
		});
		socket.on('disconnect',function(socket){
			console.log('socket disconnect');
			client.close();
			delete client;
		});
	});
	client.on('error', function (err) {
		console.log(err);
	});
	client.on('close', function () {
		console.log('modbus close');
	});
});