BACnet

Capabilities

Capability	Support	Comment
Connection state with BACnet device		See BACnet device connection monitoring
Reading value by subscription from BACnet device		See Reading values with subscription
Reading value by polling from BACnet device		See Reading values with polling
Writing value to BACnet device		See Writing values

BACnet objects/properties combination table

BACnet objects	PRESENT_VALUE	STATUS_FLAGS	OUT_OF_SERVICE	EVENT_STATE
Analog input read
Analog input write
Analog output read
Analog output write
Analog value read
Analog value write
Binary input read
Binary input write
Binary output read
Binary output write
Binary value read
Binary value write
Multi-state value read
Multi-state value write
Signed integer value read
Signed integer value write
Unsigned integer value read
Unsigned integer value write

BACnet PRESENT_VALUE/OnSphere Value type combination table

PRESENT_VALUE	DECIMAL	INTEGER	TEXT	BOOLEAN
Analog input read
Analog input write
Analog output read
Analog output write
Analog value read
Analog value write
Binary input read
Binary input write
Binary output read
Binary output write
Binary value read
Binary value write
Multi-state value read
Multi-state value write
Multi-state value read
Multi-state value write
Multi-state value read
Multi-state value write

Examples

Read a BACnet value by subscription Read a BACnet value by polling Write a BACnet value

Concept

OnSphere let the user connect to a BACnet device to write or read properties.

Difference between *_INPUT, *_OUTPUT and *_VALUE :

• *_INPUT are used for monitoring (read-only). Examples: ANALOG_INPUT (sensor reading), BINARY_INPUT (binary state), MULTI_STATE_INPUT (multi-state condition).

• *_OUTPUT are used for controlling (write-enabled). Examples: ANALOG_OUTPUT (control output to devices), BINARY_OUTPUT (binary device control), MULTI_STATE_OUTPUT (multi-state device control).

• *_VALUE are flexible object that can be both read and written, most of the time representing virtual or calculated values. Examples: ANALOG_VALUE (analog setpoints), BINARY_VALUE (binary states), MULTI_STATE_VALUE (multi-state value).

Warning

In cases where a BACnet router (BBDM) is not available, the osp-bacnet connector should be given access to the network of the bacnet device. This can only be achieved using a remote connector and starting the osp-bacnet container with the --network=host option. You can also link the bridge network and add that network to your module. Be careful the outside_access network is an overlay which does not have the same properties as a true bridge network. Refer to the overlay documentation and bridge documentation.

networks:
  [...]
  bridge:
    external:
      name: bridge

${{service-name}}:
image: ${{image-repository}}osp-bacnet${{image-version}}
networks:
  - "back"
  - "bridge"
[...]

Warning

By default the port 47808/UDP is used by the simulated device by the module.

Note

Converting a BINARY_* BACnet type to a textual value will result as active and inactive states.

BACnet device connection monitoring

The connection state between the BACnet module and a device can be read as a BOOLEAN value from the BACnet device in the OnSphere hierarchy (i.e. root.BACnet.device_123456 for example).

Warning

This value will only be updated once you try to read or write on the device.

Example

Read a BACnet value by subscription Read a BACnet value by polling Write a BACnet value

Reading values with subscription

Concept

A subscription is renewed at the value strategy frequency (defaults to 30 seconds) and has twice the lifetime, meaning the module will take at most strategyFrequency to detect an error reading the value and report it.

Usage

• SINGLE_SUBSCRIPTION : Renewable subscription monitoring changes of the presentValue property of the BACnet object in real time.

• OBJECT_SUBSCRIPTION : Renewable subscription monitoring changes of any parameters in a BACnet objet in real time. However, only changes of the PRESENT_VALUE property are reported by the module.

Example

Read a BACnet value by subscription

Reading values with polling

Concept

• MULTIPLE_POLLING : Values sharing this strategy on the same device are polled in a single read request and are read in a single response. This can lower the network overhead of the polling strategy.

• SINGLE_POLLING : Each value is polled in a dedicated read request and read in a dedicated response.

Values are polled at the value strategy frequency (defaults to 5 seconds), meaning the module will take at most strategyFrequency to detect an error reading the value and report it.

Example

Read a BACnet value by polling

Writing values

BACnet outputs allow to write :

• The present value of binary/analog outputs/values and multi state values

• The out of service property of a BACnet object

Example

Write a BACnet value