Echelon LNS - Manual (Page 51)

LNS Programmer's Guide 37
• LonMark object access
• Receiving service pin messages
• Data formatting based on standard and user-defined resource files
• Addition and removal of network variables, message tags and LonMark
Functional Blocks on host-based devices that support dynamic interface
components.
• Copying of configuration property values from one device to another
• Querying and setting of device properties, such as locations, priority slots,
self documentation, and network variable attributes
• Generation of network configuration change events
• Subnet and channel creation
• Modification of network variable types of unbound network variables
• Creating connections between devices
• Database recovery from the network
Monitor and Control
Monitoring is the process of fetching data from devices on the network, and control is the
process of writing data to network devices. Both involve subordinate tasks such as data
formatting and address change tracking (to ensure that data is not lost due to address
changes). In a L ON W ORKS network, data may be retrieved from application devices using
bound connections, polling messages at regular intervals, or explicit one-time polls.
Formatting is accomplished automatically by processing network variable types
according to predefined formatting files. Additional formatting or processing may also be
performed by the LNS application.
The first step to take when programming an LNS application is to select a client type and
initialize the LNS Object Server. Following that, you can use any of the network services
provided by LNS to perform the monitor and control (or network management) tasks
listed in these sections. Before doing so, you should review the rest of this chapter, which
describes the various client types you can use with LNS, and provides a roadmap you can
use when reading this document.
LNS Clients
LNS applications are capable of running locally or remotely. Multiple applications, some
running locally and some running remotely, can access a single network simultaneously.
A local application is one that is operating on the same PC as the LNS Server and the
LNS global database.
A remote client application is one that is running on a PC that does not contain the LNS
database or run the LNS Server. Remember that you need to use the LNS Server utility
on the LNS Server PC to enable access to the LNS Server by remote clients. If you are
using an LNS high performance (Layer 2) network interface, an application running on
your client can simultaneously access one or more local networks and one or more remote
networks using a single physical network interface (i.e. access a network database on the
application's PC as well as a network database on another PC).