Virtual controller

Contents

• Virtual controller

  • Setup

  • EAPI methods

    • action

    • get

    • list

    • set

    • var.destroy

    • var.get

    • var.list

    • var.set

    • var.set_bulk

  • Controller modes

    • Simple

    • PLC simulation

The virtual controller service allows to define virtual units and sensors, which can be used for automation tests, demos and other related purposes.

Setup

Use the template EVA_DIR/share/svc-tpl/svc-tpl-controller-virtual.yml:

bus:
  path: var/bus.ipc
command: svc/eva-controller-virtual
config:
  # basic functionality
  # auto-create virtual items on set/action
  # set true for PLC simulation
  auto_create: false
  # define virtual items
  items:
  #- sensor:tests/temp
  #- sensor:tests/hum
  #- sensor:tests/pressure
  #- sensor:tests/alarm
  #- sensor:tests/voltage
  #- sensor:tests/power
  #- unit:tests/lamp
  #- unit:tests/vent
  #- unit:tests/door
  #- unit:tests/u1
  # advanced functionality (PLC tag/var table simulation)
  # pull interval, in seconds
  #pull_interval: 1
  # pull mapping
  #pull: 
  # - var: test_array1
  #   map:
  #     - idx: 0
  #       oid: sensor:tests/temp
  #     - idx: 1
  #       oid: sensor:tests/hum
  # - var: test_var
  #   map:
  #     - oid: sensor:tests/pressure
  # - var: unit.u1
  #   map:
  #     - oid: unit:tests/u1
  # - var: unit.u2
  #   map:
  #     - oid: unit:tests/u2
  # action mapping
  #action_map:
    #unit:tests/u1:
      #var: unit.u1
    #unit:tests/u2:
      #var; unit.u2
user: nobody
workers: 1

Create the service using eva-shell:

eva svc create eva.controller.virt1 /opt/eva4/share/svc-tpl/svc-tpl-controller-virtual.yml

or using the bus CLI client:

cd /opt/eva4
cat DEPLOY.yml | ./bin/yml2mp | \
    ./sbin/bus ./var/bus.ipc rpc call eva.core svc.deploy -

(see eva.core::svc.deploy for more info)

EAPI methods

See EAPI commons for the common information about the bus, types, errors and RPC calls.

action

Description	Executes a mapped unit action
Parameters	See Unit actions
Returns	See Unit actions

get

Description	Gets controller state of a virtual item
Parameters	required
Returns	Item state struct

Parameters

Name	Type	Description	Required
i	String	Item OID	yes

Return payload example:

{
    "oid": "sensor:tests/voltage",
    "status": 1,
    "value": 25.43
}

list

Description	Lists virtual items and their states
Parameters	none
Returns	List (struct)

Return payload example:

[
    {
        "oid": "unit:tests/door",
        "status": 0,
        "value": null
    },
    {
        "oid": "sensor:tests/temp",
        "status": 1,
        "value": 42.37
    },
    {
        "oid": "sensor:tests/voltage",
        "status": 1,
        "value": 25.43
    }
]

set

Description	Sets controller state of a virtual item
Parameters	required
Returns	nothing

Parameters

Name	Type	Description	Required
i	String	Item OID	yes
status	u16	Item status	no
value	Any	Item state value	no

var.destroy

Description	Destroy virtual variable
Parameters	required
Returns	nothing

Parameters

Name	Type	Description	Required
i	String	Variable ID	yes

var.get

Description	Get virtual variable value
Parameters	required
Returns	value, single or list

Parameters

Name	Type	Description	Required
i	String	Variable ID	yes

var.list

Description	List virtual variables
Parameters	required
Returns	Virtual variables and their values

Parameters

Name	Type	Description	Required
full	bool	Full output (id/value)	no

Return payload example:

[
    {
        "id": "some.var1"
    },
    {
        "id": "some.var2"
    },
    {
        "id": "some.var3"
    }
]

var.set

Description	Set virtual variable value
Parameters	required
Returns	nothing

Parameters

Name	Type	Description	Required
i	String	Variable ID	yes
value	Any	value to set	yes

var.set_bulk

Description	Set virtual variable values in bulk
Parameters	required
Returns	Operation status: failed-to-set vars list or an empty dict

Parameters

Name	Type	Description	Required
i	Vec<String>	variable IDs	yes
values	Vec<Any>	values to set	yes

Return payload example:

{
  "failed": [ "var1" ]
}

Controller modes

The service works in two modes: Simple and PLC Simulation. The approach can be mixed in the service configuration (part of items can be mapped to virtual PLC variables while part can be mapped as simple virtual items).

Simple

If a simple configuration is used (no pull/action map), the service simulates virtual items, which states can be set via bus calls or actions.

The virtual items are mapped to EVA ICS node core as-is.

PLC simulation

When pull / action_map configuration fields are set, the service starts simulating fieldbus controller gateway behaviour, providing the same EAPI methods as fieldbus controllers to get/set PLC variables. This approach is useful when it is required to debug fieldbus mappings and events.

In PLC simulation mode item states/actions are mapped to virtual PLC variables.

The virtual variable table is stored in EVA ICS registry automatically at the service instance shutdown.

PLC variables/tag IDs can be set in any format. The variables support array indexing (VAR[idx] or VAR[start-end]) as well.

Note

In PLC simulation mode the service still uses virtual item table. It is recommended to set auto_create configuration field to true.