Tcp client

Opens a persistent TCP connection to a remote server, writes the bytes of every input record to it and, optionally, emits everything the server sends back. Use it to talk to devices or services with a raw TCP protocol.

Pins

Pin	Kind	Types	Description
Input	input	Viaducta.Plugins.UdpTypes.TcpDatagram, Viaducta.Plugins.UdpTypes.UdpDatagram, Viaducta.Plugins.TextPlugin.Types.TextRecord	Data to send.
Output	output	Viaducta.Plugins.UdpTypes.TcpDatagram	Data received from the server, with new metadata. Only active when connected.
Continue	continue	same as input	Called after the data was written, with the original input and metadata.

Configuration

Field	Type	Default	Description
Address	string	127.0.0.1	Required. Host name or IP of the TCP server.
Port	integer (1-65535)	7100	Required. Server port.
ConnectTimeOut	integer (seconds)	10	How long to wait for the connection to be established.
WriteTimeOut	integer (seconds)	5	Write timeout on the socket. 0 = no timeout.
ReadTimeOut	integer (seconds)	0	Intended read timeout, 0 = wait indefinitely (see Notes).

Behaviour

• The connection is opened on the first input record and kept open for later records (one connection per component).
• What is sent:
  • TcpDatagram / UdpDatagram: the Data bytes (IP, Port and SessionId are ignored; the target is always Address:Port).
  • TextRecord: Value encoded as UTF-8.
  • Empty data or another type throws an exception.
• Bytes are written as they are; no delimiter, length prefix or other framing is added.
• If Output has connections, a background reader is started with the connection. Each read (up to 32 KB) is emitted as one TcpDatagram with IP = Address, Port = Port, Data = received bytes and new metadata. There is no message framing: one server message can arrive split over several datagrams, or several messages in one.
• When the reader detects a lost connection and Output is connected, the next input record reconnects.
• On start the flow fails if Address is empty or Port is out of range.

Notes

• If Output has no connections, a broken connection is not re-established: later writes keep failing until the flow is restarted.
• A connect timeout is not detected as such: the subsequent write fails with a "not connected" error. A refused connection throws an exception for the record.
• ReadTimeOut has no effect, because the reader uses asynchronous reads that ignore the socket read timeout.
• Responses are not correlated with requests; if you need request/response pairing, frame and match the messages downstream.
• The error for an unsupported input type mentions "UDP"; it refers to this component.

Example

{ "Address": "10.0.0.20", "Port": 7100, "ConnectTimeOut": 10, "WriteTimeOut": 5 }

Data mapper (build TextRecord command) → Tcp client → Output → (parse device reply) → ...