Error message here!

Hide Error message here!

忘记密码?

Error message here!

请输入正确邮箱

Hide Error message here!

密码丢失?请输入您的电子邮件地址。您将收到一个重设密码链接。

Error message here!

返回登录

Close

DotNetty 实现 Modbus TCP 系列 (四) Client & Server

VictorBu 2019-02-14 14:53:00 阅读数:373 评论数:0 点赞数:0 收藏数:0

本文已收录至:开源 DotNetty 实现的 Modbus TCP/IP 协议

Client

public class ModbusClient
{
public string Ip { get; }
public int Port { get; }
public short UnitIdentifier { get; }
public IChannel Channel { get; private set; }
private MultithreadEventLoopGroup group;
private ConnectionState connectionState;
private ushort transactionIdentifier;
private readonly string handlerName = "response";
public ModbusClient(short unitIdentifier, string ip, int port = 502)
{
Ip = ip;
Port = port;
UnitIdentifier = unitIdentifier;
connectionState = ConnectionState.NotConnected;
}
public async Task Connect()
{
group = new MultithreadEventLoopGroup();
try
{
var bootstrap = new Bootstrap();
bootstrap
.Group(group)
.Channel<TcpSocketChannel>()
.Option(ChannelOption.TcpNodelay, true)
.Handler(new ActionChannelInitializer<ISocketChannel>(channel =>
{
IChannelPipeline pipeline = channel.Pipeline;
pipeline.AddLast("encoder", new ModbusEncoder());
pipeline.AddLast("decoder", new ModbusDecoder(false));
pipeline.AddLast(handlerName, new ModbusResponseHandler());
}));
connectionState = ConnectionState.Pending;
Channel = await bootstrap.ConnectAsync(new IPEndPoint(IPAddress.Parse(Ip), Port));
connectionState = ConnectionState.Connected;
}
catch (Exception exception)
{
throw exception;
}
}
public async Task Close()
{
if (ConnectionState.Connected == connectionState)
{
try
{
await Channel.CloseAsync();
}
finally
{
await group.ShutdownGracefullyAsync(TimeSpan.FromMilliseconds(100), TimeSpan.FromSeconds(1));
connectionState = ConnectionState.NotConnected;
}
}
}
public ushort CallModbusFunction(ModbusFunction function)
{
if (ConnectionState.Connected != connectionState || Channel == null)
{
throw new Exception("Not connected!");
}
SetTransactionIdentifier();
ModbusHeader header = new ModbusHeader(transactionIdentifier, UnitIdentifier);
ModbusFrame frame = new ModbusFrame(header, function);
Channel.WriteAndFlushAsync(frame);
return transactionIdentifier;
}
public T CallModbusFunctionSync<T>(ModbusFunction function) where T : ModbusFunction
{
var transactionIdentifier = CallModbusFunction(function);
var handler = (ModbusResponseHandler)Channel.Pipeline.Get(handlerName);
if (handler == null)
{
throw new Exception("Not connected!");
}
return (T)handler.GetResponse(transactionIdentifier).Function;
}
private void SetTransactionIdentifier()
{
if (transactionIdentifier < ushort.MaxValue)
{
transactionIdentifier++;
}
else
{
transactionIdentifier = 1;
}
}
public ushort ReadHoldingRegistersAsync(ushort startingAddress, ushort quantity)
{
var function = new ReadHoldingRegistersRequest(startingAddress, quantity);
return CallModbusFunction(function);
}
public ReadHoldingRegistersResponse ReadHoldingRegisters(ushort startingAddress, ushort quantity)
{
var function = new ReadHoldingRegistersRequest(startingAddress, quantity);
return CallModbusFunctionSync<ReadHoldingRegistersResponse>(function);
}
}
public enum ConnectionState
{
NotConnected = 0,
Connected = 1,
Pending = 2,
}

(文中代码仅添加了 0x03 的方法)

在 Client 中封装了 Modbus 请求方法,对同一个功能同时有同步方法(ReadHoldingRegistersAsync)和异步方法(ReadHoldingRegisters)。同步方法仅返回 TransactionIdentifier(传输标识),异步方法返回响应结果。

ModbusResponseHandler 修改为:

public class ModbusResponseHandler : SimpleChannelInboundHandler<ModbusFrame>
{
private readonly int timeoutMilliseconds = 2000;
private Dictionary<ushort, ModbusFrame> responses = new Dictionary<ushort, ModbusFrame>();
protected override void ChannelRead0(IChannelHandlerContext ctx, ModbusFrame msg)
{
responses.Add(msg.Header.TransactionIdentifier, msg);
}
public ModbusFrame GetResponse(ushort transactionIdentifier)
{
ModbusFrame frame = null;
var timeoutDateTime = DateTime.Now.AddMilliseconds(timeoutMilliseconds);
do
{
Thread.Sleep(1);
if (responses.ContainsKey(transactionIdentifier))
{
frame = responses[transactionIdentifier];
responses.Remove(transactionIdentifier);
}
}
while (frame == null && DateTime.Now < timeoutDateTime);
if(frame == null)
{
throw new Exception("No Response");
}
else if(frame.Function is ExceptionFunction)
{
throw new Exception(frame.Function.ToString());
}
return frame;
}
public override void ExceptionCaught(IChannelHandlerContext context, Exception exception)
{
context.CloseAsync();
}
}

Server

public class ModbusServer
{
private ModbusResponseService responseService;
private ServerState serverState;
public int Port { get; }
public IChannel Channel { get; private set; }
private IEventLoopGroup bossGroup;
private IEventLoopGroup workerGroup;
public ModbusServer(ModbusResponseService responseService, int port = 502)
{
this.responseService = responseService;
Port = port;
serverState = ServerState.NotStarted;
}
public async Task Start()
{
bossGroup = new MultithreadEventLoopGroup(1);
workerGroup = new MultithreadEventLoopGroup();
try
{
var bootstrap = new ServerBootstrap();
bootstrap.Group(bossGroup, workerGroup);
bootstrap
.Channel<TcpServerSocketChannel>()
.Option(ChannelOption.SoBacklog, 100)
.ChildHandler(new ActionChannelInitializer<IChannel>(channel =>
{
IChannelPipeline pipeline = channel.Pipeline;
pipeline.AddLast("encoder", new ModbusEncoder());
pipeline.AddLast("decoder", new ModbusDecoder(true));
pipeline.AddLast("request", new ModbusRequestHandler(responseService));
}));
serverState = ServerState.Starting;
Channel = await bootstrap.BindAsync(Port);
serverState = ServerState.Started;
}
finally
{
}
}
public async Task Stop()
{
if (ServerState.Starting == serverState)
{
try
{
await Channel.CloseAsync();
}
finally
{
await Task.WhenAll(
bossGroup.ShutdownGracefullyAsync(TimeSpan.FromMilliseconds(100), TimeSpan.FromSeconds(1)),
workerGroup.ShutdownGracefullyAsync(TimeSpan.FromMilliseconds(100), TimeSpan.FromSeconds(1)));
serverState = ServerState.NotStarted;
}
}
}
}
public enum ServerState
{
NotStarted = 0,
Started = 1,
Starting = 2,
}

实例化 Server 时需要传入 ModbusResponseService 的实现,实现示例:

public class ModbusResponse : ModbusResponseService
{
public override ModbusFunction ReadHoldingRegisters(ReadHoldingRegistersRequest request)
{
var registers = ReadRegisters(request.Quantity);
var response = new ReadHoldingRegistersResponse(registers);
return response;
}
private ushort[] ReadRegisters(ushort quantity)
{
var registers = new ushort[quantity];
Random ran = new Random();
for (int i = 0; i < registers.Length; i++)
{
registers[i] = (ushort)ran.Next(ushort.MinValue, ushort.MaxValue);
}
return registers;
}
}

(文中代码仅添加了 0x03 的方法)

开源地址:modbus-tcp

版权声明
本文为[VictorBu]所创,转载请带上原文链接,感谢
https://www.cnblogs.com/victorbu/p/10371056.html

编程之旅,人生之路,不止于编程,还有诗和远方。
阅代码原理,看框架知识,学企业实践;
赏诗词,读日记,踏人生之路,观世界之行;

支付宝红包,每日可领