Principles of operation
- Last UpdatedMay 29, 2026
- 1 minute read
- PI System
- Adapter for BACnet 1.2
- Adapters
The BACnet adapter's operations focus on data collection and streams creation.
Data collection
The BACnet adapter collects time-series data from selected objects on BACnet devices. The adapter supports both polling and Change of Value (, unsolicited subscription) data collection modes, as defined by the BACnet specification.
Object types and data types
The following table lists BACnet object types that the BACnet adapter supports for data collection and types of streams that will be created.
|
BACnet object type |
Stream data type |
|---|---|
|
Accumulator |
UInt32 |
|
AnalogInput |
Single |
|
AnalogOutput |
Single |
|
AnalogValue |
Single |
|
BinaryInput |
Boolean |
|
BinaryOutput |
Boolean |
|
BinaryValue |
Boolean |
|
MultistateInput |
UInt32 |
|
MultistateOutput |
UInt32 |
|
MultistateValue |
UInt32 |
Stream creation
The BACnet adapter creates a stream with two properties for a selected BACnet item. The properties are described in the following table:
|
Property name |
Data type |
Description |
|---|---|---|
|
Timestamp |
DateTime |
Timestamp of the given BACnet item value update. |
|
Value |
Specified on the type of incoming BACnet value |
Value of the BACnet item update. |
Note: If streams are deleted from an endpoint while the adapter is running, the ingress component must be restarted to recreate the streams. See Start and stop ingress component. Starting with PI Web API 2023 SP1, the PI Web API service caches the streams for 15 minutes by default. If you recreate streams within that time period, you need to restart PI Web API.