Modbus RTU Client

The Modbus RTU Client is exposed as an MbRtuClient component when a Serial instance is configured in mb_client mode.

All methods on this page require id, which identifies the MbRtuClient component instance.

Available methods:

• MbRtuClient.GetConfig
• MbRtuClient.SetConfig
• MbRtuClient.GetStatus
• MbRtuClient.ReadHoldingRegisters
• MbRtuClient.ReadInputRegisters
• MbRtuClient.ReadDiscreteInputs
• MbRtuClient.ReadCoils
• MbRtuClient.WriteHoldingRegisters
• MbRtuClient.WriteSingleRegister
• MbRtuClient.WriteCoils

Methods

MbRtuClient.GetConfig

Properties:

Property	Type	Description
id	number	MbRtuClient component instance id

Find the MbRtuClient.GetConfig response properties in Configuration

MbRtuClient.SetConfig

Properties:

Property	Type	Description
id	number	MbRtuClient component instance id
config	object	Configuration to apply

MbRtuClient.GetStatus

Properties:

Property	Type	Description
id	number	MbRtuClient component instance id

Find the MbRtuClient.GetStatus response properties in Status

MbRtuClient.ReadHoldingRegisters

Read Holding Registers (function code 0x03).

Properties:

Property	Type	Description
id	number	MbRtuClient component instance id
sid	number	Modbus server id, 1 to 247
addr	number	Start register address (0 to 65535)
qty	number	Number of registers to read, 1 to 123

Response:

Property	Type	Description
values	array of numbers	Array of 16-bit unsigned register values

MbRtuClient.ReadInputRegisters

Read Input Registers (function code 0x04).

Properties:

Property	Type	Description
id	number	MbRtuClient component instance id
sid	number	Modbus server id, 1 to 247
addr	number	Start register address (0 to 65535)
qty	number	Number of registers to read, 1 to 123

Response:

Property	Type	Description
values	array of numbers	Array of 16-bit unsigned register values

MbRtuClient.ReadDiscreteInputs

Read Discrete Inputs (function code 0x02).

Properties:

Property	Type	Description
id	number	MbRtuClient component instance id
sid	number	Modbus server id, 1 to 247
addr	number	Start bit address (0 to 65535)
qty	number	Number of bits to read, 1 to 2000

Response:

Property	Type	Description
values	array of booleans	Array of input values

MbRtuClient.ReadCoils

Read Coils (function code 0x01).

Properties:

Property	Type	Description
id	number	MbRtuClient component instance id
sid	number	Modbus server id, 1 to 247
addr	number	Start bit address (0 to 65535)
qty	number	Number of bits to read, 1 to 2000

Response:

Property	Type	Description
values	array of booleans	Array of coil values

MbRtuClient.WriteHoldingRegisters

Write Multiple Holding Registers (function code 0x10).

Properties:

Property	Type	Description
id	number	MbRtuClient component instance id
sid	number	Modbus server id, 1 to 247
addr	number	Start register address (0 to 65535)
values	array of numbers	Array of 16-bit unsigned values, 1 to 123 items

Return:

This method returns status only.

MbRtuClient.WriteSingleRegister

Write a single Holding Register (function code 0x06).

Properties:

Property	Type	Description
id	number	MbRtuClient component instance id
sid	number	Modbus server id, 1 to 247
addr	number	Register address (0 to 65535)
value	number	16-bit unsigned value (0 to 65535)

Return:

This method returns status only.

MbRtuClient.WriteCoils

Write Multiple Coils (function code 0x0F).

Properties:

Property	Type	Description
id	number	MbRtuClient component instance id
sid	number	Modbus server id, 1 to 247
addr	number	Start bit address (0 to 65535)
values	array of booleans	Array of coil values, 1 to 2000 items

Return:

This method returns status only.

Configuration

At the moment, MbRtuClient has no configurable properties.

Status

At the moment, MbRtuClient has no status properties.

Examples

MbRtuClient.ReadHoldingRegisters example

MbRtuClient.ReadHoldingRegisters HTTP GET Request

http://192.168.33.1/rpc/MbRtuClient.ReadHoldingRegisters?id=0&sid=1&addr=100&qty=2

MbRtuClient.ReadHoldingRegisters Curl Request

curl -X POST -d '{"id":1,"method":"MbRtuClient.ReadHoldingRegisters","params":{"id":0,"sid":1,"addr":100,"qty":2}}' http://${SHELLY}/rpc

MbRtuClient.ReadHoldingRegisters Mos Request

mos --port ${PORT} call MbRtuClient.ReadHoldingRegisters '{"id":0,"sid":1,"addr":100,"qty":2}'

Response

MbRtuClient.ReadHoldingRegisters HTTP GET Response

{
  "values": [
    230,
    231
  ]
}

MbRtuClient.ReadHoldingRegisters Curl Response

{
  "id": 1,
  "params": {
    "values": [
      230,
      231
    ]
  }
}

MbRtuClient.ReadHoldingRegisters Mos Response

{
  "values": [
    230,
    231
  ]
}

MbRtuClient.ReadInputRegisters example

MbRtuClient.ReadInputRegisters HTTP GET Request

http://192.168.33.1/rpc/MbRtuClient.ReadInputRegisters?id=0&sid=1&addr=300&qty=3

MbRtuClient.ReadInputRegisters Curl Request

curl -X POST -d '{"id":1,"method":"MbRtuClient.ReadInputRegisters","params":{"id":0,"sid":1,"addr":300,"qty":3}}' http://${SHELLY}/rpc

MbRtuClient.ReadInputRegisters Mos Request

mos --port ${PORT} call MbRtuClient.ReadInputRegisters '{"id":0,"sid":1,"addr":300,"qty":3}'

Response

MbRtuClient.ReadInputRegisters HTTP GET Response

{
  "values": [
    1123,
    1127,
    1131
  ]
}

MbRtuClient.ReadInputRegisters Curl Response

{
  "id": 1,
  "params": {
    "values": [
      1123,
      1127,
      1131
    ]
  }
}

MbRtuClient.ReadInputRegisters Mos Response

{
  "values": [
    1123,
    1127,
    1131
  ]
}

MbRtuClient.ReadDiscreteInputs example

MbRtuClient.ReadDiscreteInputs HTTP GET Request

http://192.168.33.1/rpc/MbRtuClient.ReadDiscreteInputs?id=0&sid=2&addr=0&qty=4

MbRtuClient.ReadDiscreteInputs Curl Request

curl -X POST -d '{"id":1,"method":"MbRtuClient.ReadDiscreteInputs","params":{"id":0,"sid":2,"addr":0,"qty":4}}' http://${SHELLY}/rpc

MbRtuClient.ReadDiscreteInputs Mos Request

mos --port ${PORT} call MbRtuClient.ReadDiscreteInputs '{"id":0,"sid":2,"addr":0,"qty":4}'

Response

MbRtuClient.ReadDiscreteInputs HTTP GET Response

{
  "values": [
    true,
    false,
    false,
    true
  ]
}

MbRtuClient.ReadDiscreteInputs Curl Response

{
  "id": 1,
  "params": {
    "values": [
      true,
      false,
      false,
      true
    ]
  }
}

MbRtuClient.ReadDiscreteInputs Mos Response

{
  "values": [
    true,
    false,
    false,
    true
  ]
}

MbRtuClient.ReadCoils example

MbRtuClient.ReadCoils HTTP GET Request

http://192.168.33.1/rpc/MbRtuClient.ReadCoils?id=0&sid=2&addr=10&qty=5

MbRtuClient.ReadCoils Curl Request

curl -X POST -d '{"id":1,"method":"MbRtuClient.ReadCoils","params":{"id":0,"sid":2,"addr":10,"qty":5}}' http://${SHELLY}/rpc

MbRtuClient.ReadCoils Mos Request

mos --port ${PORT} call MbRtuClient.ReadCoils '{"id":0,"sid":2,"addr":10,"qty":5}'

Response

MbRtuClient.ReadCoils HTTP GET Response

{
  "values": [
    false,
    true,
    true,
    false,
    false
  ]
}

MbRtuClient.ReadCoils Curl Response

{
  "id": 1,
  "params": {
    "values": [
      false,
      true,
      true,
      false,
      false
    ]
  }
}

MbRtuClient.ReadCoils Mos Response

{
  "values": [
    false,
    true,
    true,
    false,
    false
  ]
}

MbRtuClient.WriteHoldingRegisters example

MbRtuClient.WriteHoldingRegisters HTTP GET Request

http://192.168.33.1/rpc/MbRtuClient.WriteHoldingRegisters?id=0&sid=3&addr=400&values=[1000,2000]

MbRtuClient.WriteHoldingRegisters Curl Request

curl -X POST -d '{"id":1,"method":"MbRtuClient.WriteHoldingRegisters","params":{"id":0,"sid":3,"addr":400,"values":[1000,2000]}}' http://${SHELLY}/rpc

MbRtuClient.WriteHoldingRegisters Mos Request

mos --port ${PORT} call MbRtuClient.WriteHoldingRegisters '{"id":0,"sid":3,"addr":400,"values":[1000,2000]}'

Response

MbRtuClient.WriteHoldingRegisters HTTP GET Response

{}

MbRtuClient.WriteHoldingRegisters Curl Response

{
  "id": 1,
  "params": {}
}

MbRtuClient.WriteHoldingRegisters Mos Response

{}

MbRtuClient.WriteSingleRegister example

MbRtuClient.WriteSingleRegister HTTP GET Request

http://192.168.33.1/rpc/MbRtuClient.WriteSingleRegister?id=0&sid=3&addr=402&value=1234

MbRtuClient.WriteSingleRegister Curl Request

curl -X POST -d '{"id":1,"method":"MbRtuClient.WriteSingleRegister","params":{"id":0,"sid":3,"addr":402,"value":1234}}' http://${SHELLY}/rpc

MbRtuClient.WriteSingleRegister Mos Request

mos --port ${PORT} call MbRtuClient.WriteSingleRegister '{"id":0,"sid":3,"addr":402,"value":1234}'

Response

MbRtuClient.WriteSingleRegister HTTP GET Response

{}

MbRtuClient.WriteSingleRegister Curl Response

{
  "id": 1,
  "params": {}
}

MbRtuClient.WriteSingleRegister Mos Response

{}

MbRtuClient.WriteCoils example

MbRtuClient.WriteCoils HTTP GET Request

http://192.168.33.1/rpc/MbRtuClient.WriteCoils?id=0&sid=4&addr=0&values=[true,true,false,true]

MbRtuClient.WriteCoils Curl Request

curl -X POST -d '{"id":1,"method":"MbRtuClient.WriteCoils","params":{"id":0,"sid":4,"addr":0,"values":[true,true,false,true]}}' http://${SHELLY}/rpc

MbRtuClient.WriteCoils Mos Request

mos --port ${PORT} call MbRtuClient.WriteCoils '{"id":0,"sid":4,"addr":0,"values":[true,true,false,true]}'

Response

MbRtuClient.WriteCoils HTTP GET Response

{}

MbRtuClient.WriteCoils Curl Response

{
  "id": 1,
  "params": {}
}

MbRtuClient.WriteCoils Mos Response

{}

MbRtuClient.GetConfig example

MbRtuClient.GetConfig HTTP GET Request

http://192.168.33.1/rpc/MbRtuClient.GetConfig?id=0

MbRtuClient.GetConfig Curl Request

curl -X POST -d '{"id":1,"method":"MbRtuClient.GetConfig","params":{"id":0}}' http://${SHELLY}/rpc

MbRtuClient.GetConfig Mos Request

mos --port ${PORT} call MbRtuClient.GetConfig '{"id":0}'

Response

MbRtuClient.GetConfig HTTP GET Response

{}

MbRtuClient.GetConfig Curl Response

{
  "id": 1,
  "params": {}
}

MbRtuClient.GetConfig Mos Response

{}

MbRtuClient.SetConfig example

MbRtuClient.SetConfig HTTP GET Request

http://192.168.33.1/rpc/MbRtuClient.SetConfig?id=0&config={}

MbRtuClient.SetConfig Curl Request

curl -X POST -d '{"id":1,"method":"MbRtuClient.SetConfig","params":{"id":0,"config":{}}}' http://${SHELLY}/rpc

MbRtuClient.SetConfig Mos Request

mos --port ${PORT} call MbRtuClient.SetConfig '{"id":0,"config":{}}'

Response

MbRtuClient.SetConfig HTTP GET Response

{
  "restart_required": false
}

MbRtuClient.SetConfig Curl Response

{
  "id": 1,
  "params": {
    "restart_required": false
  }
}

MbRtuClient.SetConfig Mos Response

{
  "restart_required": false
}

MbRtuClient.GetStatus example

MbRtuClient.GetStatus HTTP GET Request

http://192.168.33.1/rpc/MbRtuClient.GetStatus?id=0

MbRtuClient.GetStatus Curl Request

curl -X POST -d '{"id":1,"method":"MbRtuClient.GetStatus","params":{"id":0}}' http://${SHELLY}/rpc

MbRtuClient.GetStatus Mos Request

mos --port ${PORT} call MbRtuClient.GetStatus '{"id":0}'

Response

MbRtuClient.GetStatus HTTP GET Response

{}

MbRtuClient.GetStatus Curl Response

{
  "id": 1,
  "params": {}
}

MbRtuClient.GetStatus Mos Response

{}