Glossary term
BACnet
protocoleBasics
Also known as
BACnet/IPBACnet MS/TPASHRAE 135
Definition
Open protocol for building automation and control, standardised as ASHRAE 135 and ISO 16484-5. Supports multiple physical layers (BACnet/IP, MS/TP, Ethernet). Extensible object-property model for HVAC, lighting and access control.
Source
https://www.bacnet.org/Questions using this term
- BACnet MS/TP uses a token-passing protocol between the Master nodes of an RS-485 segment: the token holder is allowed to communicate during a bounded time slot and then passes the token to the next Master in the logical ring.5. MS/TP · Token Passing
- The standard cable for BACnet MS/TP is an AWG 18-22 shielded twisted-pair with a 120 ohm characteristic impedance and capacitance below 30 pF/ft (98 pF/m), covering distances up to 1200 m at 9600 baud.22. Practical · MS/TP-Kabelspezifikation
- Wireshark ships with a native BACnet/IP dissector that allows full inspection of frames (services, objects, properties) once captured from the network; the most common display filter is "bacapp" (BACnet Application layer).12. Diagnostics · Wireshark BACnet
- BACnet relies on an object-oriented model: every device exposes Objects (e.g. Analog Input, Binary Output) that contain Properties (Present_Value, Object_Name, Description, etc.).1. Architecture · Objektorientiertes Modell
- The BACnet Multistate Value (MSV), Multistate Input (MSI) and Multistate Output (MSO) objects encode enumerations with several states (3 or more discrete values), such as HVAC modes (Comfort/Standby/Eco) or system states (Auto/Manual/Off).1. Object types · Multistate Value
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