x/modbus component: v0.29.0+ A Modbus read/write component used to perform Modbus protocol read or write operations. Supports two communication protocols: TCP and RTU.

Additional extension library required: rulego-components-iot (opens new window)

Configuration

Field	Type	Description	Default Value
server	string	Modbus server address (Format: <mode>://<host:port> or <mode>://<serial device>)	tcp://127.0.0.1:502
cmd	string	Modbus command name, supported commands include: ReadCoils, ReadDiscreteInputs, ReadRegisters, WriteCoil, WriteRegisters, etc.	ReadCoils
unitId	uint8	Unit ID (Slave ID).Format: uint8， Example: 1	1
address	string	Register address, placeholder variables ${} are allowed. Format: uint16， Example: 16	None
quantity	string	Number of registers, placeholder variables ${} are allowed	None
value	string	Register value, placeholder variables ${} are allowed. No need to provide for reading. If writing multiple values, separate them with commas. For example: 0x01,0x01, true, 51,52.	None
regType	uint	Register type, options: 0 - Holding Register(0x03) 1 - Input Register(0x04)	None
TcpConfig		TCP Configuration Parameters
timeout	int64	Request timeout in seconds	5
certPath	string	Path to the certificate (required for TLS/SSL connections)	None
keyPath	string	Path to the private key (required for TLS/SSL connections)	None
caPath	string	Path to the CA certificate (required for TLS/SSL connections)	None
RtuConfig		RTU Configuration Parameters
speed	uint	Serial baud rate (RTU mode only)	19200
dataBits	uint	Number of data bits (RTU mode only)	8
parity	uint	Parity mode (RTU mode only), options: 0 - None 1 - Even 2 - Odd	0
stopBits	uint	Number of stop bits (RTU mode only)	2
EncodingConfig		Encoding Configuration Parameters
endianness	uint	Byte order of registers, options: 1 - Big Endian 2 - Little Endian	1
wordOrder	uint	Word order for 32-bit registers, options: 1 - High Word First 2 - Low Word First	1

Command Description

Command Name	Command Description	Parameter Description
ReadCoils	Read coil statuses	address: Starting address of coils quantity: Number of coils to read
ReadCoil	Read a single coil status	address: Address of the coil
ReadDiscreteInputs	Read discrete input statuses	address: Starting address of discrete inputs quantity: Number of inputs to read
ReadDiscreteInput	Read a single discrete input status	address: Address of the discrete input
ReadRegisters	Read registers	address: Starting address of registers quantity: Number of registers to read regType: Register type (e.g., Holding Register or Input Register)
ReadRegister	Read a single register	address: Address of the register regType: Register type
ReadUint32s	Read unsigned 32-bit integers	address: Starting address of registers quantity: Number of registers to read regType: Register type
ReadUint32	Read a single unsigned 32-bit integer	address: Address of the register regType: Register type
ReadFloat32s	Read 32-bit floating-point numbers	address: Starting address of registers quantity: Number of registers to read regType: Register type
ReadFloat32	Read a single 32-bit floating-point number	address: Address of the register regType: Register type
ReadUint64s	Read unsigned 64-bit integers	address: Starting address of registers quantity: Number of registers to read regType: Register type
ReadUint64	Read a single unsigned 64-bit integer	address: Address of the register regType: Register type
ReadFloat64s	Read 64-bit floating-point numbers	address: Starting address of registers quantity: Number of registers to read regType: Register type
ReadFloat64	Read a single 64-bit floating-point number	address: Address of the register regType: Register type
ReadBytes	Read byte data	address: Starting address of registers quantity: Number of registers to read regType: Register type
ReadRawBytes	Read raw byte data	address: Starting address of registers quantity: Number of registers to read regType: Register type
WriteCoil	Write a single coil status	address: Address of the coil value: Value to write (boolean)
WriteCoils	Write multiple coil statuses	address: Starting address of coils value: Values to write (boolean array)
WriteRegister	Write a single register	address: Address of the register value: Value to write (16-bit integer)
WriteRegisters	Write multiple registers	address: Starting address of registers value: Values to write (16-bit integer array)
WriteUint32	Write a single unsigned 32-bit integer	address: Address of the register value: Value to write (32-bit integer)
WriteUint32s	Write multiple unsigned 32-bit integers	address: Starting address of registers value: Values to write (32-bit integer array)
WriteFloat32	Write a single 32-bit floating-point number	address: Address of the register value: Value to write (floating-point number)
WriteFloat32s	Write multiple 32-bit floating-point numbers	address: Starting address of registers value: Values to write (floating-point number array)
WriteUint64	Write a single unsigned 64-bit integer	address: Address of the register value: Value to write (64-bit integer)
WriteUint64s	Write multiple unsigned 64-bit integers	address: Starting address of registers value: Values to write (64-bit integer array)
WriteFloat64	Write a single 64-bit floating-point number	address: Address of the register value: Value to write (floating-point number)
WriteFloat64s	Write multiple 64-bit floating-point numbers	address: Starting address of registers value: Values to write (floating-point number array)
WriteBytes	Write byte data	address: Starting address of registers value: Values to write (byte array)
WriteRawBytes	Write raw byte data	address: Starting address of registers value: Values to write (byte array)

Relation Type

• Success: On successful execution, the message is sent to the Success chain.
• Failure: On failed execution, the message is sent to the Failure chain.

Execution Result

Write: Do not change the message payload value.

Read: Returns an array, where each element is an object containing the following fields:

• Field List

Field Name	Data Type	Description
unitId	int	Unit ID (Slave ID)
type	string	Data type, e.g., "uint16"
address	int	Address, indicating the storage location of the data
value	int float bool []byte	Current value, representing the data content

• Example Data(reading Modbus data format):

[
  {
    "unitId": 1,
    "type": "uint16",
    "address": 4,
    "value": 0
  },
  {
    "unitId": 1,
    "type": "uint16",
    "address": 5,
    "value": 0
  },
  {
    "unitId": 1,
    "type": "uint16",
    "address": 6,
    "value": 0
  },
  {
    "unitId": 1,
    "type": "uint16",
    "address": 7,
    "value": 0
  },
  {
    "unitId": 1,
    "type": "uint16",
    "address": 8,
    "value": 0
  },
  {
    "unitId": 1,
    "type": "uint16",
    "address": 9,
    "value": 0
  },
  {
    "unitId": 1,
    "type": "uint16",
    "address": 10,
    "value": 0
  },
  {
    "unitId": 1,
    "type": "uint16",
    "address": 11,
    "value": 0
  },
  {
    "unitId": 1,
    "type": "uint16",
    "address": 12,
    "value": 0
  },
  {
    "unitId": 1,
    "type": "uint16",
    "address": 13,
    "value": 0
  }
]