Modbus

https://pkg.go.dev/github.com/simonvetter/modbus
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Modbus is a Go implementation of the Modbus protocol providing both client and server components...
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### Start

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Starts the Modbus server.

```APIDOC
## Start

### Description
Starts the Modbus server.

### Function Signature
`func (ms *ModbusServer) Start() (err error)`

### Returns
- **err** (error) - An error if the server could not be started.

```

--------------------------------

### Install modbus package

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Downloads and installs the modbus package using the go get command.

```shell
$ go get github.com/simonvetter/modbus

```

--------------------------------

### func (*ModbusServer) Start

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Starts accepting client connections on the Modbus server.

```APIDOC
## func (*ModbusServer) Start

### Description
Starts accepting client connections.

### Method
Start

### Signature
func (ms *ModbusServer) Start() (err error)

### Parameters
None.

### Returns
- **err** (error) - Error if any.
```

--------------------------------

### Using the modbus client: connect, read, and write registers

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Complete client usage example for the simonvetter/modbus Go library. Covers TCP, RTU (serial), and RTU-over-TCP endpoints, connecting with Open(), reading/writing registers (single, multiple, 32/64-bit, floats, bytes), changing byte/word ordering with SetEncoding, switching unit IDs, and closing the connection.

```go
import (
    "github.com/simonvetter/modbus"
)

func main() {
    var client  *modbus.ModbusClient
    var err      error

    // for a TCP endpoint
    // (see examples/tls_client.go for TLS usage and options)
    client, err = modbus.NewClient(&modbus.ClientConfiguration{
        URL:      "tcp://hostname-or-ip-address:502",
        Timeout:  1 * time.Second,
    })
    // note: use udp:// for modbus TCP over UDP

    // for an RTU (serial) device/bus
    client, err = modbus.NewClient(&modbus.ClientConfiguration{
        URL:      "rtu:///dev/ttyUSB0",
        Speed:    19200,                   // default
        DataBits: 8,                       // default, optional
        Parity:   modbus.PARITY_NONE,      // default, optional
        StopBits: 2,                       // default if no parity, optional
        Timeout:  300 * time.Millisecond,
    })

    // for an RTU over TCP device/bus (remote serial port or
    // simple TCP-to-serial bridge)
    client, err = modbus.NewClient(&modbus.ClientConfiguration{
        URL:      "rtuovertcp://hostname-or-ip-address:502",
        Speed:    19200,                   // serial link speed
        Timeout:  1 * time.Second,
    })
    // note: use rtuoverudp:// for modbus RTU over UDP

    if err != nil {
        // error out if client creation failed
    }

    // now that the client is created and configured, attempt to connect
    err = client.Open()
    if err != nil {
        // error out if we failed to connect/open the device
        // note: multiple Open() attempts can be made on the same client until
        // the connection succeeds (i.e. err == nil), calling the constructor again
        // is unnecessary.
        // likewise, a client can be opened and closed as many times as needed.
    }

    // read a single 16-bit holding register at address 100
    var reg16   uint16
    reg16, err  = client.ReadRegister(100, modbus.HOLDING_REGISTER)
    if err != nil {
      // error out
    } else {
      // use value
      fmt.Printf("value: %v", reg16)        // as unsigned integer
      fmt.Printf("value: %v", int16(reg16)) // as signed integer
    }

    // read 4 consecutive 16-bit input registers starting at address 100
    var reg16s  []uint16
    reg16s, err = client.ReadRegisters(100, 4, modbus.INPUT_REGISTER)

    // read the same 4 consecutive 16-bit input registers as 2 32-bit integers
    var reg32s  []uint32
    reg32s, err = client.ReadUint32s(100, 2, modbus.INPUT_REGISTER)

    // read the same 4 consecutive 16-bit registers as a single 64-bit integer
    var reg64   uint64
    reg64, err  = client.ReadUint64(100, modbus.INPUT_REGISTER)

    // read the same 4 consecutive 16-bit registers as a slice of bytes
    var regBs   []byte
    regBs, err  = client.ReadBytes(100, 8, modbus.INPUT_REGISTER)

    // by default, 16-bit integers are decoded as big-endian and 32/64-bit values as
    // big-endian with the high word first.
    // change the byte/word ordering of subsequent requests to little endian, with
    // the low word first (note that the second argument only affects 32/64-bit values)
    client.SetEncoding(modbus.LITTLE_ENDIAN, modbus.LOW_WORD_FIRST)

    // read the same 4 consecutive 16-bit input registers as 2 32-bit floats
    var fl32s   []float32
    fl32s, err  = client.ReadFloat32s(100, 2, modbus.INPUT_REGISTER)

    // write -200 to 16-bit (holding) register 100, as a signed integer
    var s int16 = -200
    err         = client.WriteRegister(100, uint16(s))

    // Switch to unit ID (a.k.a. slave ID) #4
    client.SetUnitId(4)

    // write 3 floats to registers 100 to 105
    err         = client.WriteFloat32s(100, []float32{
        3.14,
        1.1,
        -783.22,
    })

    // write 0x0102030405060708 to 16-bit (holding) registers 10 through 13
    // (8 bytes i.e. 4 consecutive modbus registers)
    err         = client.WriteBytes(10, []byte{
        0x01, 0x02, 0x03, 0x04,
        0x05, 0x06, 0x07, 0x08,
    })

    // close the TCP connection/serial port
    client.Close()
}

```

--------------------------------

### Build and run modbus-cli

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Builds the CLI client from cmd/modbus-cli.go and runs it with --help to display usage information.

```shell
$ go build -o modbus-cli cmd/modbus-cli.go
$ ./modbus-cli --help

```

--------------------------------

### LoadCertPool

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Loads a PEM-encoded certificate file and returns a certificate pool.

```APIDOC
## LoadCertPool

### Description
Loads a PEM-encoded certificate file and returns a certificate pool.

### Function Signature
`func LoadCertPool(filePath string) (cp *x509.CertPool, err error)`

### Parameters
- **filePath** (string) - Required - Path to the PEM-encoded certificate file.

### Returns
- **cp** (*x509.CertPool) - The certificate pool.
- **err** (error) - An error if the file could not be loaded.

```

--------------------------------

### NewClient

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Creates, configures and returns a modbus client object.

```APIDOC
## NewClient

### Description
Creates, configures and returns a modbus client object.

### Method
NewClient

### Signature
func NewClient(conf *ClientConfiguration) (mc *ModbusClient, err error)

### Parameters
- **conf** (*ClientConfiguration) - Configuration for the modbus client.

### Returns
- **mc** (*ModbusClient) - The created modbus client object.
- **err** (error) - Error if creation failed.
```

--------------------------------

### Open

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Opens the Modbus client connection.

```APIDOC
## Open

### Description
Opens the Modbus client connection.

### Function Signature
`func (mc *ModbusClient) Open() (err error)`

### Returns
- **err** (error) - An error if the open operation failed.

```

--------------------------------

### NewServer

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Creates a new Modbus server with the given configuration and request handler.

```APIDOC
## NewServer

### Description
Creates a new Modbus server with the given configuration and request handler.

### Function Signature
`func NewServer(conf *ServerConfiguration, reqHandler RequestHandler) (ms *ModbusServer, err error)`

### Parameters
- **conf** (*ServerConfiguration) - Required - The server configuration.
- **reqHandler** (RequestHandler) - Required - The request handler.

### Returns
- **ms** (*ModbusServer) - The new Modbus server.
- **err** (error) - An error if the server could not be created.

```

--------------------------------

### NewClient

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Creates a new Modbus client with the given configuration.

```APIDOC
## NewClient

### Description
Creates a new Modbus client with the given configuration.

### Function Signature
`func NewClient(conf *ClientConfiguration) (mc *ModbusClient, err error)`

### Parameters
- **conf** (*ClientConfiguration) - Required - The client configuration.

### Returns
- **mc** (*ModbusClient) - The new Modbus client.
- **err** (error) - An error if the client could not be created.

```

--------------------------------

### Open

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Opens the underlying transport (network socket or serial line).

```APIDOC
## Open

### Description
Opens the underlying transport (network socket or serial line).

### Method
func (mc *ModbusClient) Open() (err error)
```

--------------------------------

### func NewServer

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Returns a new Modbus server with the given configuration and request handler.

```APIDOC
## func NewServer

### Description
Returns a new modbus server. reqHandler should be a user-provided handler object satisfying the RequestHandler interface.

### Method
NewServer

### Signature
func NewServer(conf *ServerConfiguration, reqHandler RequestHandler) (ms *ModbusServer, err error)

### Parameters
- **conf** (*ServerConfiguration) - Required - Server configuration.
- **reqHandler** (RequestHandler) - Required - User-provided handler implementing the RequestHandler interface.

### Returns
- **ms** (*ModbusServer) - New Modbus server instance.
- **err** (error) - Error if any.
```

--------------------------------

### ServerConfiguration

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Configuration object for the Modbus server, specifying the listening URL, timeout, max clients, TLS settings, and logger.

```APIDOC
## ServerConfiguration

### Description
Server configuration object for the Modbus server.

### Fields
- **URL** (string) - Defines where to listen at e.g. tcp://[::]:502.
- **Timeout** (time.Duration) - Sets the idle session timeout (client connections will be closed if idle for this long).
- **MaxClients** (uint) - Sets the maximum number of concurrent client connections.
- **TLSServerCert** (*tls.Certificate) - Sets the server-side TLS key pair (tcp+tls only).
- **TLSClientCAs** (*x509.CertPool) - Sets the list of CA certificates used to authenticate client connections (tcp+tls only). Leaf (i.e. client) certificates can also be used in case of self-signed certs, or if cert pinning is required.
- **Logger** (*log.Logger) - Provides a custom sink for log messages. If nil, messages will be written to stdout.
```

--------------------------------

### WriteUint64s

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes multiple 64-bit unsigned integer values.

```APIDOC
## WriteUint64s

### Description
Writes multiple 64-bit unsigned integer values.

### Function Signature
`func (mc *ModbusClient) WriteUint64s(addr uint16, values []uint64) (err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **values** ([]uint64) - Required - The unsigned integer values.

### Returns
- **err** (error) - An error if the write operation failed.

```

--------------------------------

### WriteUint32s

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes multiple 32-bit unsigned integer values.

```APIDOC
## WriteUint32s

### Description
Writes multiple 32-bit unsigned integer values.

### Function Signature
`func (mc *ModbusClient) WriteUint32s(addr uint16, values []uint32) (err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **values** ([]uint32) - Required - The unsigned integer values.

### Returns
- **err** (error) - An error if the write operation failed.

```

--------------------------------

### func (*ModbusClient) WriteUint64s

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes multiple 64-bit registers.

```APIDOC
## func (*ModbusClient) WriteUint64s

### Description
Writes multiple 64-bit registers.

### Method
WriteUint64s

### Signature
func (mc *ModbusClient) WriteUint64s(addr uint16, values []uint64) (err error)

### Parameters
- **addr** (uint16) - Required - Starting register address.
- **values** ([]uint64) - Required - Slice of values to write.

### Returns
- **err** (error) - Error if any.
```

--------------------------------

### func (*ModbusClient) WriteUint64

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes a single 64-bit register.

```APIDOC
## func (*ModbusClient) WriteUint64

### Description
Writes a single 64-bit register.

### Method
WriteUint64

### Signature
func (mc *ModbusClient) WriteUint64(addr uint16, value uint64) (err error)

### Parameters
- **addr** (uint16) - Required - Register address.
- **value** (uint64) - Required - Value to write.

### Returns
- **err** (error) - Error if any.
```

--------------------------------

### WriteUint64

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes a single 64-bit unsigned integer value.

```APIDOC
## WriteUint64

### Description
Writes a single 64-bit unsigned integer value.

### Function Signature
`func (mc *ModbusClient) WriteUint64(addr uint16, value uint64) (err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **value** (uint64) - Required - The unsigned integer value.

### Returns
- **err** (error) - An error if the write operation failed.

```

--------------------------------

### ReadUint64s

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Reads multiple 64-bit unsigned integer values.

```APIDOC
## ReadUint64s

### Description
Reads multiple 64-bit unsigned integer values.

### Function Signature
`func (mc *ModbusClient) ReadUint64s(addr uint16, quantity uint16, regType RegType) (values []uint64, err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **quantity** (uint16) - Required - The number of integers to read.
- **regType** (RegType) - Required - The register type.

### Returns
- **values** ([]uint64) - The unsigned integer values.
- **err** (error) - An error if the read operation failed.

```

--------------------------------

### func (*ModbusClient) WriteUint32

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes a single 32-bit register.

```APIDOC
## func (*ModbusClient) WriteUint32

### Description
Writes a single 32-bit register.

### Method
WriteUint32

### Signature
func (mc *ModbusClient) WriteUint32(addr uint16, value uint32) (err error)

### Parameters
- **addr** (uint16) - Required - Register address.
- **value** (uint32) - Required - Value to write.

### Returns
- **err** (error) - Error if any.
```

--------------------------------

### func (*ModbusClient) WriteUint32s

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes multiple 32-bit registers.

```APIDOC
## func (*ModbusClient) WriteUint32s

### Description
Writes multiple 32-bit registers.

### Method
WriteUint32s

### Signature
func (mc *ModbusClient) WriteUint32s(addr uint16, values []uint32) (err error)

### Parameters
- **addr** (uint16) - Required - Starting register address.
- **values** ([]uint32) - Required - Slice of values to write.

### Returns
- **err** (error) - Error if any.
```

--------------------------------

### WriteRawBytes

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes raw bytes to the specified address.

```APIDOC
## WriteRawBytes

### Description
Writes raw bytes to the specified address.

### Function Signature
`func (mc *ModbusClient) WriteRawBytes(addr uint16, values []byte) (err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **values** ([]byte) - Required - The bytes to write.

### Returns
- **err** (error) - An error if the write operation failed.

```

--------------------------------

### WriteUint32

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes a single 32-bit unsigned integer value.

```APIDOC
## WriteUint32

### Description
Writes a single 32-bit unsigned integer value.

### Function Signature
`func (mc *ModbusClient) WriteUint32(addr uint16, value uint32) (err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **value** (uint32) - Required - The unsigned integer value.

### Returns
- **err** (error) - An error if the write operation failed.

```

--------------------------------

### WriteFloat64s

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes multiple 64-bit float values.

```APIDOC
## WriteFloat64s

### Description
Writes multiple 64-bit float values.

### Function Signature
`func (mc *ModbusClient) WriteFloat64s(addr uint16, values []float64) (err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **values** ([]float64) - Required - The float values.

### Returns
- **err** (error) - An error if the write operation failed.

```

--------------------------------

### WriteRegisters

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes multiple register values.

```APIDOC
## WriteRegisters

### Description
Writes multiple register values.

### Function Signature
`func (mc *ModbusClient) WriteRegisters(addr uint16, values []uint16) (err error)`

### Parameters
- **addr** (uint16) - Required - The starting register address.
- **values** ([]uint16) - Required - The register values.

### Returns
- **err** (error) - An error if the write operation failed.

```

--------------------------------

### ReadUint32s

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Reads multiple 32-bit unsigned integer values.

```APIDOC
## ReadUint32s

### Description
Reads multiple 32-bit unsigned integer values.

### Function Signature
`func (mc *ModbusClient) ReadUint32s(addr uint16, quantity uint16, regType RegType) (values []uint32, err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **quantity** (uint16) - Required - The number of integers to read.
- **regType** (RegType) - Required - The register type.

### Returns
- **values** ([]uint32) - The unsigned integer values.
- **err** (error) - An error if the read operation failed.

```

--------------------------------

### WriteRegister

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes a single register value.

```APIDOC
## WriteRegister

### Description
Writes a single register value.

### Function Signature
`func (mc *ModbusClient) WriteRegister(addr uint16, value uint16) (err error)`

### Parameters
- **addr** (uint16) - Required - The register address.
- **value** (uint16) - Required - The register value.

### Returns
- **err** (error) - An error if the write operation failed.

```

--------------------------------

### WriteBytes

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes raw bytes to the specified address.

```APIDOC
## WriteBytes

### Description
Writes raw bytes to the specified address.

### Function Signature
`func (mc *ModbusClient) WriteBytes(addr uint16, values []byte) (err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **values** ([]byte) - Required - The bytes to write.

### Returns
- **err** (error) - An error if the write operation failed.

```

--------------------------------

### WriteFloat32s

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes multiple 32-bit float values.

```APIDOC
## WriteFloat32s

### Description
Writes multiple 32-bit float values.

### Function Signature
`func (mc *ModbusClient) WriteFloat32s(addr uint16, values []float32) (err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **values** ([]float32) - Required - The float values.

### Returns
- **err** (error) - An error if the write operation failed.

```

--------------------------------

### func (*ModbusClient) WriteRegisters

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes multiple 16-bit registers using Modbus function code 16.

```APIDOC
## func (*ModbusClient) WriteRegisters

### Description
Writes multiple 16-bit registers (function code 16).

### Method
WriteRegisters

### Signature
func (mc *ModbusClient) WriteRegisters(addr uint16, values []uint16) (err error)

### Parameters
- **addr** (uint16) - Required - Starting register address.
- **values** ([]uint16) - Required - Slice of values to write.

### Returns
- **err** (error) - Error if any.
```

--------------------------------

### WriteFloat64

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes a single 64-bit float value.

```APIDOC
## WriteFloat64

### Description
Writes a single 64-bit float value.

### Function Signature
`func (mc *ModbusClient) WriteFloat64(addr uint16, value float64) (err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **value** (float64) - Required - The float value.

### Returns
- **err** (error) - An error if the write operation failed.

```

--------------------------------

### func (*ModbusClient) WriteFloat64s

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes multiple 64-bit float registers.

```APIDOC
## func (*ModbusClient) WriteFloat64s

### Description
Writes multiple 64-bit float registers.

### Method
WriteFloat64s

### Signature
func (mc *ModbusClient) WriteFloat64s(addr uint16, values []float64) (err error)

### Parameters
- **addr** (uint16) - Required - Starting register address.
- **values** ([]float64) - Required - Slice of float values to write.

### Returns
- **err** (error) - Error if any.
```

--------------------------------

### ReadUint64

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Reads a single 64-bit unsigned integer value.

```APIDOC
## ReadUint64

### Description
Reads a single 64-bit unsigned integer value.

### Function Signature
`func (mc *ModbusClient) ReadUint64(addr uint16, regType RegType) (value uint64, err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **regType** (RegType) - Required - The register type.

### Returns
- **value** (uint64) - The unsigned integer value.
- **err** (error) - An error if the read operation failed.

```

--------------------------------

### func (*ModbusClient) WriteFloat64

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes a single 64-bit float register.

```APIDOC
## func (*ModbusClient) WriteFloat64

### Description
Writes a single 64-bit float register.

### Method
WriteFloat64

### Signature
func (mc *ModbusClient) WriteFloat64(addr uint16, value float64) (err error)

### Parameters
- **addr** (uint16) - Required - Register address.
- **value** (float64) - Required - Float value to write.

### Returns
- **err** (error) - Error if any.
```

--------------------------------

### func (*ModbusServer) Stop

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Stops accepting new client connections and closes any active session.

```APIDOC
## func (*ModbusServer) Stop

### Description
Stops accepting new client connections and closes any active session.

### Method
Stop

### Signature
func (ms *ModbusServer) Stop() (err error)

### Parameters
None.

### Returns
- **err** (error) - Error if any.
```

--------------------------------

### ReadFloat64s

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Reads multiple 64-bit float values.

```APIDOC
## ReadFloat64s

### Description
Reads multiple 64-bit float values.

### Function Signature
`func (mc *ModbusClient) ReadFloat64s(addr uint16, quantity uint16, regType RegType) (values []float64, err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **quantity** (uint16) - Required - The number of floats to read.
- **regType** (RegType) - Required - The register type.

### Returns
- **values** ([]float64) - The float values.
- **err** (error) - An error if the read operation failed.

```

--------------------------------

### func (*ModbusClient) WriteFloat32s

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes multiple 32-bit float registers.

```APIDOC
## func (*ModbusClient) WriteFloat32s

### Description
Writes multiple 32-bit float registers.

### Method
WriteFloat32s

### Signature
func (mc *ModbusClient) WriteFloat32s(addr uint16, values []float32) (err error)

### Parameters
- **addr** (uint16) - Required - Starting register address.
- **values** ([]float32) - Required - Slice of float values to write.

### Returns
- **err** (error) - Error if any.
```

--------------------------------

### ReadRegister

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Reads a single register value.

```APIDOC
## ReadRegister

### Description
Reads a single register value.

### Function Signature
`func (mc *ModbusClient) ReadRegister(addr uint16, regType RegType) (value uint16, err error)`

### Parameters
- **addr** (uint16) - Required - The register address.
- **regType** (RegType) - Required - The register type.

### Returns
- **value** (uint16) - The register value.
- **err** (error) - An error if the read operation failed.

```

--------------------------------

### func (*ModbusClient) WriteRegister

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes a single 16-bit register using Modbus function code 06.

```APIDOC
## func (*ModbusClient) WriteRegister

### Description
Writes a single 16-bit register (function code 06).

### Method
WriteRegister

### Signature
func (mc *ModbusClient) WriteRegister(addr uint16, value uint16) (err error)

### Parameters
- **addr** (uint16) - Required - Register address.
- **value** (uint16) - Required - Value to write.

### Returns
- **err** (error) - Error if any.
```

--------------------------------

### WriteFloat32

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes a single 32-bit float value.

```APIDOC
## WriteFloat32

### Description
Writes a single 32-bit float value.

### Function Signature
`func (mc *ModbusClient) WriteFloat32(addr uint16, value float32) (err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **value** (float32) - Required - The float value.

### Returns
- **err** (error) - An error if the write operation failed.

```

--------------------------------

### func (*ModbusClient) WriteFloat32

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes a single 32-bit float register.

```APIDOC
## func (*ModbusClient) WriteFloat32

### Description
Writes a single 32-bit float register.

### Method
WriteFloat32

### Signature
func (mc *ModbusClient) WriteFloat32(addr uint16, value float32) (err error)

### Parameters
- **addr** (uint16) - Required - Register address.
- **value** (float32) - Required - Float value to write.

### Returns
- **err** (error) - Error if any.
```

--------------------------------

### Close

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Closes the underlying transport.

```APIDOC
## Close

### Description
Closes the underlying transport.

### Method
func (mc *ModbusClient) Close() (err error)
```

--------------------------------

### ReadUint32

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Reads a single 32-bit unsigned integer value.

```APIDOC
## ReadUint32

### Description
Reads a single 32-bit unsigned integer value.

### Function Signature
`func (mc *ModbusClient) ReadUint32(addr uint16, regType RegType) (value uint32, err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **regType** (RegType) - Required - The register type.

### Returns
- **value** (uint32) - The unsigned integer value.
- **err** (error) - An error if the read operation failed.

```

--------------------------------

### ReadRegisters

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Reads multiple register values.

```APIDOC
## ReadRegisters

### Description
Reads multiple register values.

### Function Signature
`func (mc *ModbusClient) ReadRegisters(addr uint16, quantity uint16, regType RegType) (values []uint16, err error)`

### Parameters
- **addr** (uint16) - Required - The starting register address.
- **quantity** (uint16) - Required - The number of registers to read.
- **regType** (RegType) - Required - The register type.

### Returns
- **values** ([]uint16) - The register values.
- **err** (error) - An error if the read operation failed.

```

--------------------------------

### Stop

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Stops the Modbus server.

```APIDOC
## Stop

### Description
Stops the Modbus server.

### Function Signature
`func (ms *ModbusServer) Stop() (err error)`

### Returns
- **err** (error) - An error if the server could not be stopped.

```

--------------------------------

### RequestHandler.HandleHoldingRegisters

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Handles read holding registers (0x03), write single register (0x06), and write multiple registers (0x10) requests. The handler receives a HoldingRegistersRequest and returns a slice of register values and an error.

```APIDOC
## HandleHoldingRegisters

### Description
Handles the read holding registers (0x03), write single register (0x06) and write multiple registers (0x10) function codes. A HoldingRegistersRequest object is passed to the handler.

### Method
HandleHoldingRegisters

### Parameters
- **req** (*HoldingRegistersRequest) - Required - The request object containing the details of the holding registers operation.

### Returns
- **res** ([]uint16) - A slice of uint16 containing the register values to be sent back to the client (only sent for reads).
- **err** (error) - Either nil if no error occurred, a modbus error, or any other error.
```

--------------------------------

### ReadBytes

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Reads raw bytes from the specified address and quantity.

```APIDOC
## ReadBytes

### Description
Reads raw bytes from the specified address and quantity.

### Function Signature
`func (mc *ModbusClient) ReadBytes(addr uint16, quantity uint16, regType RegType) (values []byte, err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **quantity** (uint16) - Required - The number of bytes to read.
- **regType** (RegType) - Required - The register type (HOLDING_REGISTER or INPUT_REGISTER).

### Returns
- **values** ([]byte) - The raw bytes read.
- **err** (error) - An error if the read operation failed.

```

--------------------------------

### ReadFloat32s

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Reads multiple 32-bit float values.

```APIDOC
## ReadFloat32s

### Description
Reads multiple 32-bit float values.

### Function Signature
`func (mc *ModbusClient) ReadFloat32s(addr uint16, quantity uint16, regType RegType) (values []float32, err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **quantity** (uint16) - Required - The number of floats to read.
- **regType** (RegType) - Required - The register type.

### Returns
- **values** ([]float32) - The float values.
- **err** (error) - An error if the read operation failed.

```

--------------------------------

### Close

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Closes the Modbus client connection.

```APIDOC
## Close

### Description
Closes the Modbus client connection.

### Function Signature
`func (mc *ModbusClient) Close() (err error)`

### Returns
- **err** (error) - An error if the close operation failed.

```

--------------------------------

### SetEncoding

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Sets the endianness and word order for multi-register values.

```APIDOC
## SetEncoding

### Description
Sets the endianness and word order for multi-register values.

### Function Signature
`func (mc *ModbusClient) SetEncoding(endianness Endianness, wordOrder WordOrder) (err error)`

### Parameters
- **endianness** (Endianness) - Required - The endianness (BIG_ENDIAN or LITTLE_ENDIAN).
- **wordOrder** (WordOrder) - Required - The word order.

### Returns
- **err** (error) - An error if the operation failed.

```

--------------------------------

### ReadFloat64

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Reads a single 64-bit float value.

```APIDOC
## ReadFloat64

### Description
Reads a single 64-bit float value.

### Function Signature
`func (mc *ModbusClient) ReadFloat64(addr uint16, regType RegType) (value float64, err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **regType** (RegType) - Required - The register type.

### Returns
- **value** (float64) - The float value.
- **err** (error) - An error if the read operation failed.

```

--------------------------------

### WriteCoils

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes multiple coil values.

```APIDOC
## WriteCoils

### Description
Writes multiple coil values.

### Function Signature
`func (mc *ModbusClient) WriteCoils(addr uint16, values []bool) (err error)`

### Parameters
- **addr** (uint16) - Required - The starting coil address.
- **values** ([]bool) - Required - The coil values.

### Returns
- **err** (error) - An error if the write operation failed.

```

--------------------------------

### func (*ModbusClient) WriteCoils

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes multiple coils using Modbus function code 15.

```APIDOC
## func (*ModbusClient) WriteCoils

### Description
Writes multiple coils (function code 15).

### Method
WriteCoils

### Signature
func (mc *ModbusClient) WriteCoils(addr uint16, values []bool) (err error)

### Parameters
- **addr** (uint16) - Required - Starting coil address.
- **values** ([]bool) - Required - Slice of coil values to write.

### Returns
- **err** (error) - Error if any.
```

--------------------------------

### func (*ModbusClient) WriteRawBytes

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes raw bytes to 16-bit registers without reordering, allowing manual encoding control.

```APIDOC
## func (*ModbusClient) WriteRawBytes

### Description
Writes the given slice of bytes to 16-bit registers starting at addr. No byte or word reordering is performed: bytes are pushed to the wire as-is, allowing the caller to handle encoding/endianness/word order manually. Odd byte quantities are padded with a null byte to fall on 16-bit register boundaries.

### Method
WriteRawBytes

### Signature
func (mc *ModbusClient) WriteRawBytes(addr uint16, values []byte) (err error)

### Parameters
- **addr** (uint16) - Required - Starting register address.
- **values** ([]byte) - Required - Raw bytes to write.

### Returns
- **err** (error) - Error if any.
```

--------------------------------

### RequestHandler.HandleInputRegisters

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Handles the read input registers (0x04) function code. The handler receives an InputRegistersRequest and returns a slice of register values and an error.

```APIDOC
## HandleInputRegisters

### Description
Handles the read input registers (0x04) function code. An InputRegistersRequest object is passed to the handler.

### Method
HandleInputRegisters

### Parameters
- **req** (*InputRegistersRequest) - Required - The request object containing the details of the input registers operation.

### Returns
- **res** ([]uint16) - A slice of uint16 containing the register values to be sent back to the client.
- **err** (error) - Either nil if no error occurred, a modbus error, or any other error.
```

--------------------------------

### ReadRawBytes

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Reads raw bytes from the specified address and quantity.

```APIDOC
## ReadRawBytes

### Description
Reads raw bytes from the specified address and quantity.

### Function Signature
`func (mc *ModbusClient) ReadRawBytes(addr uint16, quantity uint16, regType RegType) (values []byte, err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **quantity** (uint16) - Required - The number of bytes to read.
- **regType** (RegType) - Required - The register type.

### Returns
- **values** ([]byte) - The raw bytes read.
- **err** (error) - An error if the read operation failed.

```

--------------------------------

### ReadDiscreteInputs

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Reads multiple discrete input values.

```APIDOC
## ReadDiscreteInputs

### Description
Reads multiple discrete input values.

### Function Signature
`func (mc *ModbusClient) ReadDiscreteInputs(addr uint16, quantity uint16) (values []bool, err error)`

### Parameters
- **addr** (uint16) - Required - The starting discrete input address.
- **quantity** (uint16) - Required - The number of discrete inputs to read.

### Returns
- **values** ([]bool) - The discrete input values.
- **err** (error) - An error if the read operation failed.

```

--------------------------------

### SetUnitId

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Sets the Modbus unit ID.

```APIDOC
## SetUnitId

### Description
Sets the Modbus unit ID.

### Function Signature
`func (mc *ModbusClient) SetUnitId(id uint8) (err error)`

### Parameters
- **id** (uint8) - Required - The unit ID.

### Returns
- **err** (error) - An error if the operation failed.

```

--------------------------------

### WriteCoil

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes a single coil value.

```APIDOC
## WriteCoil

### Description
Writes a single coil value.

### Function Signature
`func (mc *ModbusClient) WriteCoil(addr uint16, value bool) (err error)`

### Parameters
- **addr** (uint16) - Required - The coil address.
- **value** (bool) - Required - The coil value.

### Returns
- **err** (error) - An error if the write operation failed.

```

--------------------------------

### ReadFloat32

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Reads a single 32-bit float value.

```APIDOC
## ReadFloat32

### Description
Reads a single 32-bit float value.

### Function Signature
`func (mc *ModbusClient) ReadFloat32(addr uint16, regType RegType) (value float32, err error)`

### Parameters
- **addr** (uint16) - Required - The starting address.
- **regType** (RegType) - Required - The register type.

### Returns
- **value** (float32) - The float value.
- **err** (error) - An error if the read operation failed.

```

--------------------------------

### func (*ModbusClient) WriteCoil

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes a single coil using Modbus function code 05.

```APIDOC
## func (*ModbusClient) WriteCoil

### Description
Writes a single coil (function code 05).

### Method
WriteCoil

### Signature
func (mc *ModbusClient) WriteCoil(addr uint16, value bool) (err error)

### Parameters
- **addr** (uint16) - Required - Coil address.
- **value** (bool) - Required - Coil value to write (true or false).

### Returns
- **err** (error) - Error if any.
```

--------------------------------

### ReadCoils

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Reads multiple coil values.

```APIDOC
## ReadCoils

### Description
Reads multiple coil values.

### Function Signature
`func (mc *ModbusClient) ReadCoils(addr uint16, quantity uint16) (values []bool, err error)`

### Parameters
- **addr** (uint16) - Required - The starting coil address.
- **quantity** (uint16) - Required - The number of coils to read.

### Returns
- **values** ([]bool) - The coil values.
- **err** (error) - An error if the read operation failed.

```

--------------------------------

### ReadDiscreteInput

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Reads a single discrete input value.

```APIDOC
## ReadDiscreteInput

### Description
Reads a single discrete input value.

### Function Signature
`func (mc *ModbusClient) ReadDiscreteInput(addr uint16) (value bool, err error)`

### Parameters
- **addr** (uint16) - Required - The discrete input address.

### Returns
- **value** (bool) - The discrete input value.
- **err** (error) - An error if the read operation failed.

```

--------------------------------

### type RequestHandler interface

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Interface for handling Modbus requests on the server side, including coils and discrete inputs.

```APIDOC
## type RequestHandler interface

### Description
Interface for handling Modbus requests on the server side. Implement this interface to process incoming requests.

### Methods

#### HandleCoils

Handles the read coils (0x01), write single coil (0x05) and write multiple coils (0x0f) function codes. A CoilsRequest object is passed to the handler.

Expected return values:
- res: a slice of bools containing the coil values to be sent back to the client (only sent for reads),
- err: either nil if no error occurred, a modbus error (see mapErrorToExceptionCode() in modbus.go for a complete list), or any other error. If nil, a positive modbus response is sent back to the client along with the returned data. If non-nil, a negative modbus response is sent back, with the exception code set depending on the error.

Signature: HandleCoils(req *CoilsRequest) (res []bool, err error)

#### HandleDiscreteInputs

Handles the read discrete inputs (0x02) function code. A DiscreteInputsRequest object is passed to the handler.

Expected return values:
- res: a slice of bools containing the discrete input values to be sent back to the client,
- err: either nil if no error occurred, a modbus error (see mapErrorToExceptionCode() in modbus.go for a complete list), or any other error.

Signature: HandleDiscreteInputs(req *DiscreteInputsRequest) (res []bool, err error)
```

--------------------------------

### ReadCoil

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Reads a single coil value.

```APIDOC
## ReadCoil

### Description
Reads a single coil value.

### Function Signature
`func (mc *ModbusClient) ReadCoil(addr uint16) (value bool, err error)`

### Parameters
- **addr** (uint16) - Required - The coil address.

### Returns
- **value** (bool) - The coil value.
- **err** (error) - An error if the read operation failed.

```

--------------------------------

### WriteCoilValue

Source: https://pkg.go.dev/github.com/simonvetter/modbus

Writes a single coil value using a raw payload.

```APIDOC
## WriteCoilValue

### Description
Writes a single coil value using a raw payload.

### Function Signature
`func (mc *ModbusClient) WriteCoilValue(addr uint16, payload uint16) (err error)`

### Parameters
- **addr** (uint16) - Required - The coil address.
- **payload** (uint16) - Required - The raw coil payload.

### Returns
- **err** (error) - An error if the write operation failed.

```
Tokens:
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