Documentation ¶
Index ¶
- Constants
- Variables
- func ConnectRTU(serialDevice string, baudRate int) (io.ReadWriteCloser, error)
- func ConnectTCP(server string, port int) (net.Conn, error)
- func DecodeHiLo(data []byte) (int16, error)
- func DisconnectRTU(ctx io.ReadWriteCloser)
- func DisconnectTCP(conn net.Conn)
- func RTURead(serialDeviceConnection io.ReadWriteCloser, slaveAddress, functionCode byte, ...) ([]byte, error)
- func RTUWrite(serialDeviceConnection io.ReadWriteCloser, slaveAddress, functionCode byte, ...) ([]byte, error)
- func TCPRead(conn net.Conn, timeOut, transactionID int, functionCode byte, ...) ([]byte, error)
- func TCPWrite(conn net.Conn, timeOut, transactionID int, functionCode byte, ...) ([]byte, error)
- func ValidFunction(fnCode byte) bool
- func ValidReadFunction(fnCode byte) bool
- func ValidWriteFunction(fnCode byte) bool
- type RTUFrame
- type TCPFrame
Constants ¶
const ( MODBUS_PORT = 502 RTU_FRAME_MAXSIZE = 512 TCP_FRAME_MAXSIZE = 260 FUNCTION_READ_COILS = 0x01 FUNCTION_READ_DISCRETE_INPUTS = 0x02 FUNCTION_READ_HOLDING_REGISTERS = 0x03 FUNCTION_READ_INPUT_REGISTERS = 0x04 FUNCTION_WRITE_SINGLE_COIL = 0x05 FUNCTION_WRITE_SINGLE_REGISTER = 0x06 FUNCTION_WRITE_MULTIPLE_REGISTERS = 0x10 FUNCTION_MODBUS_ENCAPSULATED_INTERFACE = 0x2B EXCEPTION_UNSPECIFIED = 0x00 // catch-all for unspecified modbus errors EXCEPTION_ILLEGAL_FUNCTION = 0x01 EXCEPTION_DATA_ADDRESS = 0x02 EXCEPTION_DATA_VALUE = 0x03 EXCEPTION_SLAVE_DEVICE_FAILURE = 0x04 EXCEPTION_ACKNOWLEDGE = 0x05 EXCEPTION_SLAVE_DEVICE_BUSY = 0x06 EXCEPTION_MEMORY_PARITY_ERROR = 0x08 EXCEPTION_GATEWAY_PATH_UNAVAILABLE = 0x0A EXCEPTION_GATEWAY_TARGET_DEVICE_FAILED_TO_RESPOND = 0x0B EXCEPTION_BAD_CHECKSUM = 0xff // this is not official )
Variables ¶
var MODBUS_EXCEPTIONS = map[uint16]error{ EXCEPTION_UNSPECIFIED: errors.New("Modbus Error"), EXCEPTION_ILLEGAL_FUNCTION: errors.New("Modbus Error: Illegal Function (0x01)"), EXCEPTION_DATA_ADDRESS: errors.New("Modbus Error: Data Address (0x02)"), EXCEPTION_DATA_VALUE: errors.New("Modbus Error: Data Value (0x03)"), EXCEPTION_SLAVE_DEVICE_FAILURE: errors.New("Modbus Error: Slave Device Failure (0x04)"), EXCEPTION_ACKNOWLEDGE: errors.New("Modbus Error: Acknowledge (0x05)"), EXCEPTION_SLAVE_DEVICE_BUSY: errors.New("Modbus Error: Slave Device Busy (0x06)"), EXCEPTION_MEMORY_PARITY_ERROR: errors.New("Modbus Error: Memory Parity Error (0x08)"), EXCEPTION_GATEWAY_PATH_UNAVAILABLE: errors.New("Modbus Error: Gateway Path Unavailable (0x0A)"), EXCEPTION_GATEWAY_TARGET_DEVICE_FAILED_TO_RESPOND: errors.New("Modbus Error: Gateway Target Device Failed to Respond (0x0B)"), EXCEPTION_BAD_CHECKSUM: errors.New("Modbus Error: Bad Checksum"), }
Functions ¶
func ConnectRTU ¶
func ConnectRTU(serialDevice string, baudRate int) (io.ReadWriteCloser, error)
ConnectRTU attempts to access the Serial Device for subsequent RTU writes and response reads from the modbus slave device
func ConnectTCP ¶
ConnectTCP attempts to make a tcp connection to the given server/port and returns the connection object (or nil, if fail) and an error (which will be nil on success)
func DecodeHiLo ¶
DecodeHiLo attempts to convert a byte array of High/Low Byte values into a 16-bit integer, and returns the result, also with an error, which will be non-nil if the decoding failed.
func DisconnectRTU ¶
func DisconnectRTU(ctx io.ReadWriteCloser)
DisconnectRTU closes the underlying Serial Device connection
func DisconnectTCP ¶
func RTURead ¶
func RTURead(serialDeviceConnection io.ReadWriteCloser, slaveAddress, functionCode byte, startRegister, numRegisters uint16, timeOut int, debug bool) ([]byte, error)
RTURead performs the given modbus Read function over RTU to the given serialDevice, using the given frame data
func RTUWrite ¶
func RTUWrite(serialDeviceConnection io.ReadWriteCloser, slaveAddress, functionCode byte, startRegister, numRegisters uint16, data []byte, timeOut int, debug bool) ([]byte, error)
RTUWrite performs the given modbus Write function over RTU to the given serialDevice, using the given frame data
func TCPRead ¶
func TCPRead(conn net.Conn, timeOut, transactionID int, functionCode byte, serialBridge bool, slaveAddress byte, data []byte, debug bool) ([]byte, error)
TCPRead performs the given modbus Read function over TCP to the given host/port combination, using the given frame data
func TCPWrite ¶
func TCPWrite(conn net.Conn, timeOut, transactionID int, functionCode byte, serialBridge bool, slaveAddress byte, data []byte, debug bool) ([]byte, error)
TCPWrite performs the given modbus Write function over TCP to the given host/port combination, using the given frame data
func ValidFunction ¶
ValidFunction returns a boolean, depending on whether or not the given code corresponds to a valid modbus function code, read, write, or interface
func ValidReadFunction ¶
ValidReadFunction returns a boolean, depending on whether or not the given code corresponds to a valid modbus read function code
func ValidWriteFunction ¶
ValidWriteFunction returns a boolean, depending on whether or not the given code corresponds to a valid modbus write function code
Types ¶
type RTUFrame ¶
type RTUFrame struct { TimeoutInMilliseconds int SlaveAddress byte FunctionCode byte StartRegister uint16 NumberOfRegisters uint16 Data []byte }
func (*RTUFrame) GenerateRTUFrame ¶
GenerateRTUFrame is a method corresponding to a RTUFrame object which returns a byte array representing the associated serial line/RTU application data unit (ADU)
type TCPFrame ¶
type TCPFrame struct { TimeoutInMilliseconds int DebugTrace bool TransactionID int FunctionCode byte EthernetToSerialBridge bool SlaveAddress byte Data []byte }
func (*TCPFrame) GenerateTCPFrame ¶
GenerateTCPFrame is a method corresponding to a TCPFrame object which returns a byte array representing the associated TCP/IP application data unit (ADU)
func (*TCPFrame) TransmitAndReceive ¶
TransmitAndReceive is a method corresponding to a TCPFrame object which generates the corresponding ADU, transmits it to the modbus server (slave device) specified by the TCP address+port, and returns a byte array of the slave device's reply, and error (if any)