Efficient building management with Topkapi
using BACnet protocol
An open communication protocol widely used in the HVAC industry, BACnet has become a de facto standard and a global norm. Each year, this communication protocol is increasingly used in the building industry to meet expectations for energy performance and controlled facility management.
In response to this observation and to meet the needs of industry players, Topkapi SCADA software is equipped with a native protocol driver that allows integrated and simplified configuration with BACnet communicating equipment. Objectives: time and cost savings in the development and maintenance of supervision applications.
BACnet protocol & Topkapi
Object explorer and softlink assistant
The explorer allows you to view all BACnet objects, their properties, and to select the data to be incorporated into the supervision:
- Selections by complete objects or individual properties
- Selection filters (on names, types, properties)
- Free association of each type of object to a model (supplied), customizable without programming
- Several templates are provided for each type of BACnet object to cover the needs with very few adaptations.
- Support for all common objects, including Calendar, Scheduler, Trend Log, Event Log(1)
- The priority level of the remote controls is individually adjustable
(1) Contact us for a detailed list of supported objects and properties, and to receive the PICS (Protocol Implementation Conformance Statement).
Equipment addressing capacities
The BACnet driver of Topkapi SCADA software has been designed to cover all the BACnet addressing possibilities and to allow a wide segmentation of the networks in order to optimize the use of bandwidth.
In BACnet IP networks, Topkapi SCADA software offers the following possibilities:
- Simultaneous support for multiple network interfaces/adapters and IP addresses
- Simultaneous support of multiple ports on a single IP address
- Support for IP VPN networks
- Support of networks with NAT (Network Address Translation)
- Support for networks with TP routers/Firewall
Topkapi SCADA software also supports any BACnet network other than BACnet IP, via a BACnet router.
Several types of equipment addressing are supported simultaneously, on demand, on the same communication port:
- Direct static addressing
- Static addressing via a router
- Dynamic addressing
- Dynamic addressing via BBMD
The use of broadcast type messages is normally limited to one-off network discovery actions in configuration mode.
Optimization of data exchanges
Optimal management of exchanges is ensured by :
- Network segmentation capacity: see paragraph above.
- Optimization of the feedback of information (VOC method - change of value)
- Direct setting from Topkapi of object properties such as Deadband or sample rate (configuration mode)
- Monitoring of the BACnet 'Link Status' Parameter
- Automatic data re-subscription after a change of PLC program
For real-time data, during the parameterization and exploration phase of the PLC variables, Topkapi systematically subscribes to the data in VOC mode (change of value) when it is available in this form.
When the VOC method of subscribing to variations is not possible, the feedback of information can be done by periodic reading with an adjustable periodicity, or only on operator command.
The feedback of time-stamped values at the source(2) (Trend Log and Event Log) is done by freely combining three possible methods :
- Adjustable periodicity
- Operator request
- BUFFER READY type PLC event, or any other application-specific condition
The optimization of time-stamped exchanges is based on :
- A differential feedback according to the BACnet 135-2008 standard
- Support for large data packets (1024 segmented packets) limiting the number of requests (the size is adjustable to fit the PLC capabilities if needed)
(2)Requires that the Topkapi version ordered has the option to manage time-stamped data at source.