HW definitions

HW definitions are in /etc/evok/hw_definitions/. Each file represents one Modbus device.

File structure

Name of the file is the device code, which is then entered into the Evok configuration.

modbus_register_blocks

Contains a list of Modbus register groups. These registers must be placed consecutively. When reading the device, it is read in one command. Each element contains the following parameters:

• start_reg
• count
• frequency - represents the number by which the frequency is divided. The actual frequency is then entered separately for each device. Learn more in Evok configuration.
• type - register type, defaults to holding.

modbus_features

Contains a list of devices and their required parameters. Each element contains the following parameters:

• type - device type, supported devices are listed below.
• count - number of devices of the type, register addresses incremented based on this number

Other commands depend on the specific type of device.

Example

---
# This key defines which Modbus registers will be periodically read. Each block (also sometimes referred to as "group") is read once ever ["frequency"] read cycles
modbus_register_blocks:
    - start_reg   : 0
      count       : 10
      frequency   : 1

    - start_reg   : 500
      count       : 8
      frequency   : 10

    - start_reg   : 508
      count       : 8
      frequency   : 50

# This defines the devices mapped to the registers above. As custom devices are very unlikely to support any Neuron features, the only devices which should be mapped are "REGISTER"s
modbus_features: 
    - type        : REGISTER
      count       : 10
      start_reg   : 0

    - type        : REGISTER
      count       : 8
      start_reg   : 500

    - type        : REGISTER
      count       : 8
      start_reg   : 508

Supported device types

DO (digital output)

Parameters

• val_reg
  • Value register address
  • bitmask
• pwm_reg
  • PWM duty register address
• pwm_ps_reg
  • PWM prescale register address
• pwm_c_reg
  • PWM cycle register address
• val_coil
  • DO coil address
• modes
  • List of available DO modes
  • Supported: [Simple, PWM]

Example

  - type        : DO
    count       : 4
    modes       :
      - Simple
      - PWM
    val_reg     : 1
    val_coil    : 0
    pwm_reg     : 16
    pwm_ps_reg  : 1017
    pwm_c_reg   : 1018

RO (relay output)

Parameters

• val_reg
  • Value register address
  • bitmask
• val_coil
  • RO coil address

Example

  - type        : RO
    count       : 5
    val_reg     : 1
    val_coil    : 0

DI (Digital input)

Parameters

• val_reg
  • Value register address
  • bitmask
• counter_reg
  • Counter register address
  • Double register
• deboun_reg
  • Debounce register address
• modes
  • List of available DI modes
  • Supported: [Simple, DirectSwitch]
• ds_modes
  • List of available direct switch modes
  • Supported: [Simple, Inverted, Toggle]
• direct_reg
  • Direct switch register address
• polar_reg
  • Polarity register address
• toggle_reg
  • Toggle register address

Example

  - type        : DI
    count       : 4
    modes       :
      - Simple
      - DirectSwitch
    ds_modes    :
      - Simple
      - Inverted
      - Toggle
    val_reg     : 0
    counter_reg : 16
    direct_reg  : 1016
    deboun_reg  : 1010
    polar_reg   : 1017
    toggle_reg  : 1018

AO (analog output)

Parameters

• val_reg
  • Value register address
• modes
  • List of available modes
  • Modes are available in the API under these names
  • Every mode must define following parameters:
    • unit
      • Measure unit
    • range
      • Min and max measure values define in array
• mode_reg
  • Mode register address

Example

  - type        : AO
    count       : 4
    modes       :
      Voltage:
        unit: 'V'
        range: [0, 10]
    min_v       : 0
    max_v       : 10
    val_reg     : 2

AI (analog input)

Parameters

• val_reg
  • Value register address
• mode_reg
  • Mode register address
• modes
  • List of available modes
  • Modes are available in the API under these names
  • Every mode must define following parameters:
    • value
      • Value in mode_reg
    • unit
      • Measure unit
    • range
      • Min and max measure values define in array

Example

- type        : AI
  count       : 4
  val_reg     : 6
  mode_reg    : 1019
  modes       :
    Disabled:
      value: 0
    Voltage10:
      value: 1
      unit: 'V'
      range: [0, 10]
    Voltage2V5:
      value: 2
      unit: 'V'
      range: [0, 2.5]
    Current20m:
      value: 3
      unit: 'mA'
      range: [0, 20]
    Resistance3W:
      value: 4
      unit: 'Ohm'
      range: [0, 1960]
    Resistance2W:
      value: 5
      unit: 'Ohm'
      range: [0, 100000]

WD (watchdog)

Parameters

• val_reg
  • Value register address
• timeout_reg
  • timeout register address
• nv_save_coil
  • nv save coil address
• reset_coil
  • reset coil address

Example

  - type        : WD
    count       : 1
    val_reg     : 6
    timeout_reg : 1008
    nv_sav_coil : 1003
    reset_coil  : 1002

REGISTER (Modbus register)

Parameters

• start_reg
  • Start Modbus register address

Example

  - type        : REGISTER
    count       : 21
    start_reg   : 0

DATA_POINT (Data point)

Parameters

• name
  • Value name
• unit
  • Value unit
• value_reg
  • Value register address
• datatype
  • value data type
  • supported: [null, float32]

Example

- type        : DATA_POINT
  name        : "temperature"
  count       : 1
  value_reg   : 0
  unit        : "°C"
  datatype    : float32