ABOUT LONWORKS

FREQUENTLY ASKED QUESTIONS ABOUT LONWORKS:

WHAT IS AN EXAMPLE OF A SIMPLE LONWORKS SYSTEM?

A simple lighting control network would be a single switch controlling several relays. In a Douglas Lonworks system, the switch and relays interconnect to Douglas WNX-2624 Nodes which each have a neuron. When the switch is turned ON or OFF, its Node sends an activation signal with the input # of the switch flagged. The Nodes all 'listen' for that input # and will trigger any connected relays that are assigned to it.

FOR NETWORKS, WHAT IS 'CONFIGURING', 'ASSIGNING' AND 'BINDING'?

A LonWorks network consists of devices that are configured to send/receive signals to/from other devices in the network. Configuring determines which input devices send which messages to which output devices and in what manner. Assigning or Binding means a specific input can send a specific signal to a specific output. For most commercially-available Lonworks systems, configuration must be done by a System Integrator using an external PC (computer). In the Douglas self-configuring W-2000 Lonworks lighting control system, however, configuration is automatically done at power up and an Integrator is not required.

WHAT IS A 'SYSTEM INTEGRATOR' AND DO I NEED ONE?

A System Integrator is an individual, usually a designer or contractor, who can integrate different systems together to provide building-specific solutions and installations. Most systems installed in buildings are stand-alone systems that require no integration. Hardwired systems, where outputs of one system are directly wired to inputs of another, do not require an Integrator. Systems that are directly connected by a digital signal usually do not require an Integrator. Integrated systems that use a common method of control, or so-called 'open systems', usually do require the services of a System Integrator.

The above are very brief explanations. For more detailed explanations go to:

Detailed Answers to LonWorks FAQ.pdf

LONWORKS DOWNLOADS FOR LONWORKS PRODUCTS

.xif files and plug-ins for several Douglas Lonworks devices are available for System Integrators.

The device .xif files simulate the device for use in off-line system design and configuration.

The device plug-ins are graphical interfaces that permit easy monitoring, configuring and controlling of the device using the LNS LonMaker software engine.

To download .xif files, or to request plug-insfor Douglas Lonworks products, go to: LonWorks Downloads.

LONWORKS LINKS

To find out more about LonWorks, the following links are provided for your convenience. Echelon Corporation and the LonMark Association maintain extensive websites that provide information about the LonWorks system and LonMark certified products and integrators.

Echelon Corporation Home Page
LonWorks Overview, Echelon Corp. Website
LonMark Association Home Page

HOW LONWORK DEVICES WORK

A Lonworks control network consists of physical components called devices (or 'nodes') that each perform specific functions.

Each device has associated with it a number of Objects that pertain to the device's overall function. It is important to appreciate that an object is not a physical entity, but rather a software entity that is embedded in the neuron chip contained in the device. If the device has several functions, it can contain several objects with which to affect those functions.

On the LonWorks network, messages are transmitted between the objects rather than the devices themselves. Messages are also referred to as Network Variables. Objects each have a Functional Profile, which is a description of the Network Variables the object is capable of receiving and sending. Objects each also have a specific set of Configuration Properties.

Object diagrams show the network variables contained in each object, the configuration properties and how they interrelate. Below is an object diagram for the Douglas WNX-2624 Network Node.



The Network Node has the objects Scene Panel, which receives the relay group status and issues group commands in response, and Lighting Panel Controller which receives the group commands and issues the relay group status in response. These objects communicate because they both utilize the Standard Network Variable Type SNVT_Scene. In like manner, objects Switch, which issues commands to activate a switch, and Lamp Actuator, which receives switch commands and activates a relay in response, communicate because they both utilize the Standard Network Variable Type SNVT_Switch. All these objects utilize the Standard Configuration Property Type SCPTLocation.

For additional information, go to:

LonWorks: Definition of Terms.pdf
Douglas LonWorks Products Overview.pdf