ROAMview to BACnet IP Software Module

Specifications

  • Features
  • Software interface to BMS/BAS Systems over BACnet IP
  • Change of Value Reporting
  • Device Data collection
  • Write Property support to control lamps
  • BACnet PICS Information
  • Vendor Name: Lithonia Lighting
  • Product Name: ROAMnet
  • Software Version: ROAMview 2.2a+
  • Data Link Layer: BACnet IP, (Annex J)
  • Character Set Supported: ANSI X3.4
  • Segmentation: Not Supported
  • Configurable Parameters:
  • Polling Interval ( data retrieval from database )
  • Virtual Network Address ( first 2 octets )
  • Local BACnet Port
  • Command Parameters
  • Dim Parameters

Overview

The ROAMviewBACnet IP Software Module allows a Building Management System ( BMS ) to communicate with the ROAMview system. This software module functions as a software gateway to the devices on the ROAMview mesh network, receiving and translating BACnet IP messages from any BMS system and then transmitting them over the ROAMview mesh network. Response message from the ROAMview mesh network are then similarly transmitted and communicated back via BACnet IP to the BMS system. Additionally, this software gateway will allow BMS system to subscribe for Change Of Value notifications from the devices.

This interface is a BACnet/IP software solution that runs as a windows service on the ROAMview server. Placing it on the ROAMview server ensures that the service is always active as long as the ROAMview system is running. Since BACnet is not resident on any of the ROAM hardware devices, this software module manages all BACnet communication on behalf of the hardware. The following requests for ROAM device information are supported:

  • Read current relay state
  • Read current dim level
  • Firmware version
  • Model Name
  • Changes in relay state
  • Change in dim level

All individual devices are enumerated automatically and are made available for reading via the BMS controller. The software module emulates a virtual network so that it does not use any IP addresses of the existing network.

Detailed Implementation Description

Change of Value

All BACnet devices on the ROAM system will support a Change of Value subscription for the relay state of the lamp. A Change of Value event will be sent anytime the lamp turns on or turns off. The BACnet devices that support dimming will also support a Change of Value subscription for the dim level of the lamp. A Change of Value event will be sent anytime the dim level is changed.

Data Collection

The frequency of data collection from the ROAM system is determined by a configuration setting in the software. The frequency can be set as low as 10 seconds and as high as 60 seconds. Whenever this threshold is reached, the software module will refresh the data from the devices and store the latest values in memory. Change of Value notifications will be sent when this occurs if any devices have subscribers.

Lamp/Dim Control

The Software module will accept Write Property messages to control the relay state and dim level of the ROAMview devices. Because the ROAMview devices require a time duration to be included with each command, it is not possible to send just the relay state or dim level in the Write Property Messages. To account for this, a list of command values are stored in the configuration file for the Software Module. These values are included as an example and are customer configurable. When the Write Property messages are sent to the software module, it would use one of the command values. The system will perform a lookup and issue the appropriate commands to the devices.

Group Control

In addition to exposing a BACnet device for each ROAMview device in the system, the software module will also expose BACnet devices for each group in the ROAMview system. This will allow commands to be issued to all of the devices within each group, however the groups will not expose an object where the Present Value can be read since all of the devices within the group may not be functioning in the same manner.

Protocol Implementation Conformance Statement

The following BACnet service requests are supported:

Confirmed Request

Read Property

Write Property

Subscribe COV

Unconfirmed Request

Who-Is

I-Am

Complex ACK

Simple ACK

BACnet Interoperability Building Blocks ( Annex K )

DS-RP-B / Data Sharing-ReadProperty-B
DS-WP-B / Data Sharing-WriteProperty-B
DS-COV-B / Data Sharing-COV-B
DM-DDB-B / Device Management-Dynamic Device Binding-B

Each ROAMviewBACnet device contains 3-5 BACnet Objects:

  • OBJECT_DEVICE:1
  • The BACnet device object will contain information about the hardware.
  • OBJECT_BINARY_INPUT:2
  • The Present Value of this object will contain the relay state of the lamp
  • 0 = lamp is off
  • 1 = lamp is on
  • This object will accept CoV subscription requests
  • OBJECT_ANALOG_OUTPUT:3
  • This object will accept Write Property request of the Present Value to turn the lamp on,off or return it to photocontrol.
  • OBJECT_ANALOG_INPUT:4 (will only appear for devices that support dimming )
  • The Present Value of this object will contain the dim level of the lamp, where the value is a percent of luminosity desired.
  • 0 = most dim
  • 100 = brightest
  • OBJECT_ANALOG_OUTPUT:5 ( will only appear for devices that support dimming)
  • This object will accept Write Property Requests of the Present Value to dim the lamp

Each ROAMviewBACnetgroup device contains 1-3BACnet Objects:

  • OBJECT_DEVICE:1
  • The BACnet device object will contain information about the hardware.
  • OBJECT_ANALOG_OUTPUT:3
  • This object will accept Write Property request of the Present Value to turn the lamp on,off or return it to photocontrol.
  • OBJECT_ANALOG_OUTPUT:5 ( will only appear for devices that support dimming)
  • This object will accept Write Property Requests of the Present Value to dim the lamp

ROAMView Object / Access / BACnet Object Type / Instance Number
Device / R / Device / 1
Relay State / R / Binary Input / 2
Relay State / W / Analog Output / 3
Dim Level / R / Analog Input / 4
Dim Level / W / Analog Output / 5

Binary Input Object

Property Identifier / Property Data Type / Access
Object_Identifier / BACnetObjectIdentifier / R
Event_State / BACnetEventState / R
Object_Name / CharacterString / R
Object_Type / BACnetObjectType / R
Out_Of_Service / BOOLEAN / R
Polarity / BACnetPolarity / R
Present Value / REAL / R
Status Flags / BACnetStatusFlags / R

Analog Output Object

Property Identifier / Property Data Type / Access
Object_Identifier / BACnetObjectIdentifier / R
Event_State / BACnetEventState / R
Object_Name / CharacterString / R
Object_Type / BACnetObjectType / R
Out_Of_Service / BOOLEAN / R
Present_Value / REAL / W
Status_Flags / BACnetStatusFlags / R
Units / BACnetEngineeringUnits / R

Analog Input Object

Property Identifier / Property Data Type / Access
Object_Identifier / BACnetObjectIdentifier / R
Event_State / BACnetEventState / R
Object_Name / CharacterString / R
Object_Type / BACnetObjectType / R
Out_Of_Service / BOOLEAN / R
Present_Value / REAL / R
Status_Falgs / BACnetStatusFlags / R
Units / BACnetEngineeringUnits / R