tcp

func (*TCPClientHandler) Close ¶

func (mb *TCPClientHandler) Close() error

Close closes current connection.

func (*TCPClientHandler) Connect ¶

func (mb *TCPClientHandler) Connect() error

Connect establishes a new connection to the address in Address. Connect and Close are exported so that multiple requests can be done with one session

func (*TCPClientHandler) Decode ¶

func (mb *TCPClientHandler) Decode(adu []byte) (pdu *modbus.ProtocolDataUnit, err error)

Decode extracts PDU from TCP frame:

Transaction identifier: 2 bytes
Protocol identifier: 2 bytes
Length: 2 bytes
Unit identifier: 1 byte

func (*TCPClientHandler) Encode ¶

func (mb *TCPClientHandler) Encode(pdu *modbus.ProtocolDataUnit) (adu []byte, err error)

Encode adds modbus application protocol header:

Transaction identifier: 2 bytes
Protocol identifier: 2 bytes
Length: 2 bytes
Unit identifier: 1 byte
Function code: 1 byte
Data: n bytes

func (*TCPClientHandler) Received ¶

func (mb *TCPClientHandler) Received(handler func(data []byte))

处理服务端响应

func (*TCPClientHandler) Send ¶

func (mb *TCPClientHandler) Send(aduRequest []byte) (aduResponse []byte, err error)

Send sends data to server and ensures response length is greater than header length.

func (*TCPClientHandler) Verify ¶

func (mb *TCPClientHandler) Verify(aduRequest []byte, aduResponse []byte) (err error)

Verify confirms transaction, protocol and unit id.