Modbus Adaptor

Introduction

Modbus is a master/slave protocol, the device requesting the information is called the Modbus master and the devices supplying information are Modbus slaves. In a standard Modbus network, there is one master and up to 247 slaves, each with a unique slave address from 1 to 247. The master can also write information to the slaves.

Modbus adaptor implements the goburrow/modbus to support both TCP and RTU protocols, it acting as the controller(master) node and connects to or manipulating the Modbus worker(slave) devices on the edge side.

Modbus Registers Operation

• Coil Registers: readable and writable, 1 bit (off/on)

• Discrete Input Registers: readable, 1 bit (off/on)

• Input Registers: readable, 16 bits (0 to 65,535), essentially measurements and statuses

• Holding Registers: readable and writable, 16 bits (0 to 65,535), essentially configuration values

Registration Information

Versions	Register Name	Endpoint Socket	Available
v1alpha1	adaptors.edge.cattle.io/modbus	modbus.sock	*

Support Model

Kind	Group	Version	Available
ModbusDevice	devices.edge.cattle.io	v1alpha1	*

Support Platform

OS	Arch
linux	amd64
linux	arm
linux	arm64

Usage

$ kubectl apply -f https://raw.githubusercontent.com/cnrancher/octopus/master/adaptors/modbus/deploy/e2e/all_in_one.yaml

Authority

Grant permissions to Octopus as below:

Resources Non-Resource URLs Resource Names Verbs

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

modbusdevices.devices.edge.cattle.io [] [] [create delete get list patch update watch]

modbusdevices.devices.edge.cattle.io/status [] [] [get patch update]

Example

• Specifies a ModbusDevice device link to connect a serial port thermometer.

  apiVersion: edge.cattle.io/v1alpha1

  kind: DeviceLink

  metadata:

  name: modbus-rtu

  spec:

  adaptor:

  node: edge-worker

  name: adaptors.edge.cattle.io/modbus

  model:

  apiVersion: "devices.edge.cattle.io/v1alpha1"

  kind: "ModbusDevice"

  template:

  metadata:

  labels:

  device: modbus-rtu

  spec:

  parameters:

  syncInterval: 10s

  timeout: 10s

  protocol:

  rtu:

  endpoint: /dev/tty.usbserial-1410

  workerID: 1

  parity: "N"

  stopBits: 2

  dataBits: 8

  baudRate: 9600

  properties:

  - name: temperature

  description: data collection of temperature sensor

  readOnly: true

  visitor:

  register: HoldingRegister

  offset: 0

  quantity: 1

  orderOfOperations:

  - type: Divide

  value: "10"

  type: float

For more ModbusDevice device link examples, please refer to the deploy/e2e directory and make a quick experience with deploy/e2e/simulator.yaml.

ModbusDevice

Parameter	Description	Schema	Required
metadata		metav1.ObjectMeta	false
spec	Defines the desired state of ModbusDevice.	ModbusDeviceSpec	true
status	Defines the observed state of ModbusDevice.	ModbusDeviceStatus	false

ModbusDeviceSpec

Parameter	Description	Schema	Required
extension	Specifies the extension of device.	*ModbusDeviceExtension	false
parameters	Specifies the parameters of device.	*ModbusDeviceParameters	false
protocol	Specifies the protocol for accessing the device.	*ModbusDeviceProtocol	true
properties	Specifies the properties of device.	[]ModbusDeviceProperty	false

ModbusDeviceStatus

Parameter	Description	Schema	Required
properties	Reports the properties of device.	[]ModbusDeviceStatusProperty	false

ModbusDeviceParameters

Parameter	Description	Schema	Required
syncInterval	Specifies the amount of interval that synchronized to limb, default to 15s.	string	false
timeout	Specifies the amount of timeout, default to 10s.	string	false

ModbusDeviceProtocol

Parameter	Description	Schema	Required
rtu	Specifies the connection protocol as RTU.	*ModbusDeviceProtocolRTU	false
tcp	Specifies the connection protocol as TCP.	*ModbusDeviceProtocolTCP	false

ModbusDeviceProtocolRTU

Parameter	Description	Schema	Required
endpoint	Specifies the serial port of device, which is in form of "/dev/ttyS0".	string	true
workerID	Specifies the worker ID of device.	int	true
baudRate	Specifies the baud rate of connection, a measurement of transmission speed, default to 19200.	int	false
dataBits	Specifies the data bit of connection, selected from [5, 6, 7, 8], default to 8.	int	false
parity	Specifies the parity of connection, selected from [N - None, E - Even, O - Odd], the use of N(None) parity requires 2 stop bits, default to E.	string	false
stopBits	Specifies the stop bit of connection, selected from [1, 2],the use of N(None) parity requires 2 stop bits, default to 1.	int	false

ModbusDeviceProtocolTCP

Parameter	Description	Schema	Required
endpoint	Specifies the IP address of device, which is in form of "ip:port".	string	true
workerID	Specifies the worker ID of device.	int	true

ModbusDeviceProperty

Parameter	Description	Schema	Required
name	Specifies the name of property.	string	true
description	Specifies the description of property.	string	false
type	Specifies the type of property.	ModbusDevicePropertyType	true
visitor	Specifies the visitor of property.	*ModbusDevicePropertyVisitor	true
readOnly	Specifies if the property is readonly., default to false.	boolean	false
value	Specifies the value of property, only available in the writable property.	string	false

ModbusDeviceStatusProperty

Parameter	Description	Schema	Required
name	Reports the name of property.	string	false
type	Reports the type of property.	ModbusDevicePropertyType	false
value	Reports the value of property.	string	false
updatedAt	Reports the updated timestamp of property.	*metav1.Time	false

ModbusDevicePropertyType

Parameter	Description	Schema
string	Property data type is string.	string
int	Property data type is int.	string
float	Property data type is float.	string
boolean	Property data type is boolean.	string

ModbusDevicePropertyVisitor

Parameter	Description	Schema	Required
register	Specifies the register to visit.	ModbusDeviceRegisterType	true
offset	Specifies the starting offset of register for read/write data.	int	true
quantity	Specifies the quantity of register.	int	true
orderOfOperations	Specifies the operations in order if needed.	[]ModbusDeviceArithmeticOperation	false

ModbusDeviceRegisterType

Parameter	Description	Schema
CoilRegister	Readable and writable, 1 bit (off/on).	string
DiscreteInputRegister	Readonly, 1 bit (off/on).	string
InputRegister	Readonly, 16 bits (0 to 65,535), essentially measurements and statuses.	string
HoldingRegister	Readable and writable, 16 bits (0 to 65,535), essentially configuration values.	string

ModbusDeviceArithmeticOperation

Parameter	Description	Schema	Required
type	Specifies the type of arithmetic operation.	ModbusDeviceArithmeticOperationType	false
value	Specifies the value for arithmetic operation, which is in form of float string.	string	false

ModbusDeviceArithmeticOperationType

Parameter	Description	Schema
Add	Arithmetic operation of add.	string
Subtract	Arithmetic operation of subtract.	string
Multiply	Arithmetic operation of multiply.	string
Divide	Arithmetic operation of divide.	string

ModbusDeviceExtension

Parameter	Description	Schema	Required
mqtt	Specifies the MQTT settings.	*v1alpha1.MQTTOptionsSpec	false