【 Weak current College 】 LonWorks control networks in building automation in typical applications

-------BAS-K3000 building automation system

ThetypicalapplicationofLonWorkscontrolnetworktechnologyonBuildingAutomaticSystem-------BAS-K3000BuildingAutomaticSystem
Foshan CMG intelligent automation engineering co., Ltd. Ho Tong Shan

Summary: LonWorks control networks is a next-generation technology, with its open and flexible, and other characteristics to become a building automation system. This article to Guangdong Development Bank Foshan branch guangfa building automation system used by the instance, explains BAS-K3000 as LonWorks control networks in building automatic control system of typical applications and design several problems.

Abstract:LonWorkstechnologyisthenewgenerationofthecontrolnetworkingtechnology,Asaopen、flexiblesystem,ItbecomesthebestchoiceofBuildingAutomaticSystem(BAS).Thistheme,onbackgroundofBAS-K3000systemusedintheBASofGUANGFAbuilding,describethetypicalapplicationofLonWorkscontrolnetworktechnologyonBASandsomeitemswhichshouldbepaidattention.

Keywords: LonWorks, building automation system, intelligent distributed control nodes,

keywords:LonWorks,BuildingAutomaticSystem,Intelligentnode,distributedControl

Since the early 1990s United States Echelon Corporation developed the first piece of Neuron Chip, the LonWorks control networks technology has penetrated into the control field in every corner. In escape from exclusive control programmes and central control system, LonWorks control networks at the forefront. As a revolutionary control system, LonWorks control networks technology to its openness, flexibility, low cost and rapid development of features in the building automation, industrial automation and home automation has made notable achievements. Internationally renowned-controlled companies are already preparing to launch based on the LonWorks control networks technology products. One of the earliest application LonWorks control networks engineering unit of the CMG intelligent automation engineering company, based in recent years in building automation success experience developed BASK3000 building automation system, control the LonWorks network technology in the building automation in typical applications.

First, why use LonWorks control networks technology

Traditional centralized control system, the remote sensor provides feedback to the central controller signals, each system has its own I/O and processing procedures, which resulted in the development, installation, debugging complex, costly, and extensibility. System designers a lot of energy in transmission line and communications.

LonWorks control networks technology has many advantages, the focus is reflected in:

1. system and provide the openness and interoperability.

LonWorks network consists of nodes (that is, the intelligent controller was through curing in internal meet OSI seven-layer reference model LONTALK network communication protocol of the Internet, forming a "PeertoPeer" peer-to-peer networks, developers can simply place the main effort in the system application design without requires specialized to implement and test the transmission lines and distribution systems.

2. distributed without central control.

Network node near field sensors and actuators, each node can complete control and communication functions, part node failures may not cause system crashes, can be up to nine monitoring station can be easily installed in the network of any location, and location can always transform, monitoring stations feature completely peer-to-peer, or you can define a different level. These features on the system of debugging, maintenance, and stability are important.

3. system configuration flexibility, short development cycle, the application of a wide range of media.

Using different types of transceivers, the system can use twisted pair, fiber optic cable, coaxial cables, power line, wireless, infrared, and other media for signal transmission; according to the transport distance, speed, and field equipment, and other specific requirements free topology or the bus type, structure, to system design and maintenance upgrade brings great convenience.

II. Summary of BASK3000 system constitute

BAS-K3000 building automation system in full compliance with LonWorks control networks standard communication protocol--LONTALK, takes full advantage of LonWorks technology for control and communication functions, the network consists of:

Intelligent node

Network interface and connection devices

Remote communication equipment

Man-machine interface action station

1. intelligent node

Intelligent node is closest toField device controllers, sensors, actuators, through digital and analog input/output, you can make data acquisition, receipt, and send instructions. By Echelon Corporation provides transceivers include: TP/TP/XF-1250 XF-78, bus, TP/twisted pair FTT-10A free topology twisted-pair type, style, and so can PLC-10 engine constituted the appropriate network topology.

Intelligent node provided monitoring features include digital input, digital output, analog input, analog output, and standard system clock, etc.

System underlying the application writes the node's memory, each node can independently perform collection and control directive, the can and the other nodes in a peer-to-peer network communication.

2. network interface and connection devices

Network interface adapter is operating station and network communication equipment, using LONTALK Protocol to communicate. PCLTA (PCLonTalkAdapter) is an ISA card, insert the PC to communicate with the LonWorks network. SLTA/2 and SLTA-10A (SerialLonTalkAdapter) is EIA-232 serial port adapter, the network through a standard serial interface and Exchange data.

Network-attached devices mainly refers to the routers used to connect different topology or different communication media of the subnet or channel, LonWorks router consists of two modules, respectively connecting two communication channels, with LonWorks router can be thousands of node installation to the network.

3. remote communication equipment

The system can be realized through a telephone line, wireless spectrum or over the Internet, distance monitoring control network extends to all parts of the world.

4. Human-machine interface action station

Unlike previous centralized control system Center, this operator station and is not a network data exchange Center, but only to operators on the network for monitoring and control of the interface, complete system monitoring and network management features. Network management features including setting system parameters, select the monitor mode, definitions and replace nodes, and monitoring capabilities include monitoring system running status, monitor, system fault alarm, control equipment and stopping or valve opening, etc.

III. BAS-K3000 building automation system monitor objects and functions

BAS-K3000 building automation system to modern buildings for a comprehensive, flexible, reliable monitoring, including central air conditioning system, cooling system, boiler/hot swap system, water supply and drainage systems, distribution systems, lighting, lighting system, elevator systems, anti-theft security system monitoring. The subsystem can operate independently and harmonization of management, the entire building electrical energy-efficient, safe and reliable running.

1. the central air conditioning system

* Monitor the chillers operating status

* In the prescribed order remote/automatic control unit commitment

Post order to: cooling tower valve-cooling water valve-cooling water pump-frozen water valve-cooling water pump-water chillers (cooling tower fan with temperature regulation) shut down in reverse order

* Refrigeration/cooling electric butterfly valve opening and closing of the control and valve position status display.

* Refrigeration/cooling water pump start-up and shutdown control and fault alarm.

* Refrigeration/cooling water in and out of the water flow, temperature, pressure, and other parameters of the acquisition and recording.

* According to the actual cooling loads real-time adjustment of chillers starting number and on frozen water pump for frequency control to save energy.

* Fresh air and environmental temperature and humidity monitoring.

* New fans, air handlers, send/exhaust fan and stopping control, proportional control valve to open degree control and valve position status display.

* Fire-fighting system, fire resistance, on sent/exhaust fan.

* The above equipment according to predetermined schedule automatic start and stop.

* Depending on the cooling tower water temperature controlled cooling fan stops immediately.

2. cold energy billing system

* Record for fan coil solenoid valve opening time accumulated.

* Record air processor ratio control valve flow through the cumulative flow chilled water.

* Statistics, print, central air conditioning cooling capacity charges.

3. boiler/hot swap system

* Boiler steam temperature and pressure monitoring.

* Vacuum boiler steam temperature, after pressure monitoring.

* Heat exchanger work status monitoring.

* Heat exchanger for return water temperature, flow, pressure monitoring.

* Control of heating pump stops and condition monitoring.

4. the distribution system

* Transformer temperature monitoring and alarm.

* Distribution Cabinet of voltage, current, active power, reactive power, power factor, such as monitoring and alarm.

* Switch cabinet each branch of switch status monitoring, relay protection status monitoring.

* Generator work status monitoring, oil temperature over-temperature alarm, etc.

5. water supply and sewerage system

* To start the automatic rotation of the pump, condition monitoring and fault alarm.

* The system pressure, level, flow monitoring.

6. lighting system

* Based on the functional requirements of the differentFor area light switch and illumination control

* Depending on the subscription schedule zone control lights and stopping.

* According to the environmental illuminance control lighting system of illumination.

7. lift system

* Monitor the elevator in the running state.

* Monitor the elevator floor.

* Linkage with fire protection systems and stopping forced controlled elevator

8. anti-theft security system

* Through network interfaces with other subsystems of the Internet.

* On the alarm signal to the electronic map to quickly locate,

BAS-K3000 system operator interface software

Based on the operating system's 9X MICROSOFTWINDOWS3.X/Chinese dynamic graphical interface that is easy to follow tips on Chinese, almost no training to complete most of the action. Its main features are:

1. for the subsystem device for comprehensive monitoring and control

System applications and basic parameters saved in the memory of intelligent nodes, node blackout will not be lost, intelligent node can independently perform data acquisition, and device control functionality. The interface allows the operator to control directly.

1) in the graphical user interface to access the subsystem interface.

2) in the graphics interface on dynamic real-time display devices work status, system parameters (including the refrigeration/cooling water supply/return water temperature, pressure, flow, valve opening, carbon monoxide etc.). Central air conditioning system cooler source system interface to all relevant equipment in a screen display simultaneously, enabling the operator to across the Board, to prevent errors, to avoid the frequent conversion menu.

3) using the graphical button control on the device.

4) using graphics and sound alarm reporting equipment operation breakdown.

2. system initialization and parameter setting for the first time using this system is initialized.

1) neutral operator, modify the password.

2) defines the operator permissions, the appropriate level of qualified operators operating range.

3) changes in the system function modules.

4) set the device to stop timetable.

5) set the cooling tower temperature adjustment range.

6) set the converter parameter.

7) on cold energy billing system can be set to a different time period rate receivable.

3. history of query, statistics, analysis

1) scheduled acquisition records

-Frozen water supply/return water temperature, flow, pressure value.

-Cooling water supply/return water temperature, flow, pressure value.

-Fresh air/air/air temperature.

-Boiler/heat exchanger steam temperature and pressure values.

-Electrical voltage, current, active power, reactive power, power factor, etc.

-Drainage system of pressure, flow, level, etc.

2) fault alarm automatically records

-Water chillers and refrigeration/cooling water pump, etc.

-Refrigeration/cooling water over-temperature, overpressure alarm.

-A new fan, hood, filter clogging alarm.

-Boiler steam over-temperature, overpressure alarm.

-Distribution system overload, over-temperature alarm.

-Elevator malfunction alarm.

-Drainage water level alarm.

-Anti-theft security trigger alarm.

For more detailed information can be recorded alarm failure type, time of occurrence, resolution time, etc.

3) history of conditional queries, statistics, and print the report.

-With text, charts, and other ways to facilitate user access

-Replace the manual record, find tedious work.

-In case of need the contents of the report will be logged into file to print.

IV. examples of projects

Guangdong Development Bank Foshan branch guangfa building automation system:

Guangfa building 22-storey building, with an area of 30 000 square meters, is divided into the device layer, Park, Bank Office and Foreign Office. Building the smart house design, installation of advanced integrated wiring systems and building automation system, where the building automation system uses the Foshan CMG intelligent automation engineering company developed based on the LonWorks control networks BAS-K3000 system. System total 370 monitoring point. System monitoring operations station located on the second floor, intelligent node is dispersed in the vicinity of field equipment. Due to the system as a non-central control mode, the operating stations may transform position.

System software operating system for Chinese WINDOWS95, interface graphics are very realistic and friendly image, graphic dynamically represents the equipment operation, such as grey means that the device off State, purple means the device open status, chiller flow switch opens the flow of color will change. The entire system including a central air-conditioning equipment monitoring and charging two most chilling. The operator can be used in each floor plan on monitoring to the floor of the main air conditioning devices running status and whether the failure information, if you want to know more detailed information, you can use the mouse to click on the graphic symbols for the device to go to the next level of menu, detailed monitoring of the device.

System everyOne hour sampling data, including the air conditioning system freezing water total back water, chilled water supply/return water temperature, cooling water temperature for/backwater, in the action interface can query these parameters of history, charts reflect the trend of individual quantities.

System fault alarm function module can automatically record the types of alarming, time of occurrence and the time, the operator can always query to all alarm occurred or all processed alarm recording.

This system in May 1998 and, through acceptance of commissioning, running properly.

5. Design based on LonWorks technology building automatic control system of the

1. should make full use of LonWorks network technology truly distributed, decentralized arrangements as nodes in a location close to the on-site equipment to reduce the wiring effort and increasing transport reliability.

2. from the perspective of the underlying software design, you should try to control a device with the corresponding data collection point arrangement on the same node, aims to reduce network variables in Internet traffic, and reduce unnecessary loss of information, improving the reliability of the transmission, while also simplifying the complexity of the program design. For example, a cooling tower and stopping control is determined by the level of the cooling tower water temperature, so if possible you should try to set the temperature acquisition points and control points for the start-up and shut-down of the cooling tower at the same node.

3. the whole system of intelligent node should be centralized power supply. Reduce part node blackout caused by inconsistency in the system parameters.

4. should adopt new models of networking products, try not to use the obsolete products, and pay attention to the matching between products. For example LonworksTP/XF78K, TP/XF125K module now has basically not produced, instead of their corresponding FTT-10A module, is the network interface from the original SLTA/2 updated to SLTA-10.

5. should pay special attention to a symbol of quality, it is often installed without being seriously but often system defects. For example, the flow meter installation requirements before and after a certain length of straight pipe distance, if you are not guaranteed, then the measure of the flow is likely to be inaccurate. Again such as flow switch installation thread casing pipe diameter should be large enough to ensure that the angle of the blade swing freely enough make contact.

VI. concluding remarks

We welcomed by national Ministry of construction and other government departments is to promote the LonWorks control networks in domestic is unprecedented speed of development, advanced technology and always will be accepted, and believe that our building automation levels in this lead will soon forward into the ranks of world advanced level.

Reference documents:

1. Zhang Rui Wu, "intelligent building", Tsinghua University Press, 1996

2. Guo Zhi-ming, "intelligent building technologies and development of" intelligent building, 1997.5 (1)

3. Guo Chun Hing, "building automation system to the latest technologies-BAS LonWorks" intelligent building, 1998.6 (5)

4. Omar, Liang, an introduction to the "intelligent building", the Chinese construction industry press, 1996