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DIRIS Digiware D-50 & D-70 - 548088B - SOCOMEC
ANNEx II.
BACNET COMMUNICATION WITH THE DIRIS DI
-
GIWARE D-50 / D-70
The DIRIS Digiware D-50 / D-70 supports the BACnet IP protocol.
It acts as a BACnet IP gateway to all devices compatible and connected downstream via RS485 or the Digiware Bus.
The PICS (Protocol Implementation Conformance Statement) of the DIRIS Digiware D-50 / D-70 is available on the
Socomec website at
www.socomec.com
.
Annex II - 1. BACnet Generalities
BACnet provides a method for computer-based control equipment from different manufacturers to be interoperable.
BACnet is designed to handle many types of building controls, including HVAC, lighting, security, fire, access control,
maintenance, waste management and so forth.
Common terms used in BACnet communication:
Object:
Represents a device and its data. Multiple objects type can be available for each device *analog input, binary
input…). Each object has a number of properties which fully describe the BACnet object to the network.
Object identifier:
Uniquely identifies an object within a BACnet device.
Property:
A property describes a BACnet object to the network.
Present value:
It is one of the properties of the Analog_Input Object. It represents the current value of an analog input
object.
Service:
Message type between one BACnet device to another.
BACnet uses a client/server communication mode between devices. Devices communicate between each other using
services describing the type of exchange.
A BACnet client is a device that requests a service, and a BACnet server is a device that executes a service.
Data inside a BACnet device is organized as a series of objects, each composed of multiple properties.
Ex: the analog_input object defines a property for present_value, a property for average_value etc…
A BACnet client initiates a request to a BACnet server using a service (ex: read_property) to a specific property (ex:
present_value) contained in a BACnet object (ex: analog_input).
Annex II - 2. BACnet Objects
BACnet defines a standard set of “Objects”, each of which has a standard set of “Properties” describing the object and its
current status to other devices on the BACnet internetwork. The properties allow for the object to be controlled by other
BACnet devices.
BACnet defines 54 objects. Each element of the building control system is represented by one or more objects.
The DIRIS Digiware M-50 / M-70 supports the below Objects:
OBJECT TYPE
EXEMPLE OF USE
Device
To describe the device to the BACnet network.
Analog input
Instantaneous current for phase 1 (I1) measured by a DIRIS Digiware I-xx current module
with associated current sensor
Binary input
Status (ON/OFF) of an auxiliary contact
Binary output
Change of status of the output of a DIRIS Digiware IO-10
