Echelon LNS - Manual (Page 50)

LNS Programmer's Guide 36
LNS Network Services
The primary purpose of the LNS network operating system is to simplify the
performance of network services. Network services are operations that fall into the
following three major categories:
• Network installation and configuration
• Network maintenance and repair
• System monitoring and control
The first two categories are collectively called network management. The third category
is called monitor and control.
A simple network service typically results in the transmission of multiple LonTalk
messages across the network. When the application requests a service, e.g. to connect a
set of network variables, the LNS Object Server translates the request into LNS service
calls which are then expanded into the required network actions — allocating network
resources; building, sending, and processing network messages; performing error
checking and recovery. The result of the request is routed back to the LNS Object Server,
which notifies the application if an error has occurred.
By selecting the appropriate object and invoking its methods, an LNS application can
quickly accomplish each network management task with a minimum of overhead. The
LNS Object Server manages the device and network resources for the application, and
sends and processes the required LonTalk messages.
The LNS Object Server automates network-related tasks whenever possible. You can
configure it to automatically discover the presence of newly attached devices on the network.
Where automation is not possible, simplification is provided. For example, the LNS Object
Server provides connection description objects that allow the LNS application to specify all
the attributes of a connection in a single object. As a result, an application can choose a pre-
existing connection description when connecting two devices, instead of manually specifying
each attribute of the connection. By adding application knowledge (for example, the set of
devices that it may encounter and the types of configurations that make sense), an application
can further automate tasks and simplify the user interface.
The LNS Object Server provides these core network services to LNS applications. See the
sections following this for a more detailed overview of network services that can be
applied to network management tasks, and services that can be applied to monitor and
control tasks.
Network Management
LNS provides all the network services you need to install, configure, and manage a
network with your application. This includes the following:
• Device discovery, installation, configuration, removal, replacement,
resetting, testing, and management
• Router installation, configuration, removal, replacement, testing, and
management
• Importing device self-documentation and self-identification information
ad hoc or through external interface files
• Connection and disconnection of network variables and message tags