Opening the object server, Selecting a network interface, Opening the – Echelon LNS User Manual

Page 68: Selecting a, Network, Interface

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LNS Programmer's Guide

54

Application Developer’s Kit CD-ROM jewel case. For more information on LNS licensing,

and for more details on the differences between Standard Mode and Demonstration
Mode, see Chapter 13, LNS Licensing.

Opening the Object Server

Once you have set the network access and license modes, you can open the Object Server,

as shown below:
ObjectServer.Open()


NOTE: If you will be opening any networks with an LNS application that is running as a

Windows service, then the first application to open the LNS Object Server must also be

running as a Windows service. In addition, if a network is to be opened by an LNS

application that is running as Windows service, then that network and system must be
opened by an LNS application that is running as Windows service before it is opened

with an LNS application running as a user process. For more information on this, consult
the help pages for the Open() methods of the Network and ObjectServer objects in

the LNS Object Server Reference help file.

Selecting a Network Interface

Local clients can access a record of the possible networks and servers from the LNS

global database. In contrast, each Full client application must register with the LNS

Server in order to interact with a network. Each Full client does so by querying the
L

ON

W

ORKS

network it’s attached to for available servers.

Each Full client applications must specify its network interface prior to having access to

the available servers and networks. You can do so by following these steps:

1. Fetch

the

NetworkInterfaces collection from the ObjectServer

object. All network interfaces registered in the Windows System Registry

on your application PC are automatically read by the Object Server, and
are included in this collection.

Dim NICollection as LcaNetworkInterfaces

Set NICollection = ObjectServer.NetworkInterfaces

2. Select the desired network interface. Remember that the

NetworkInterfaces collection contains all registered network

interfaces, including those that are not suitable for use with LNS.

NOTE: In LNS 3.0 and all subsequent releases, if multiple Full Client

applications on the same PC attempt to open the same network, they
must use the same network interface. Consider a case where you have

two PCLTA-20 network interface cards called LON1 and LON2 on a PC

that is running several Full client applications. If an application on that
PC opens a network using LON1, and then another application on the PC

attempts to open the same network using LON2, the second application
will receive the NS#149 lcaErrNsConflictWithCurrentNetwork

exception when it attempts to open the network. However, the second

application will be able to successfully open the network using LON1.

The following code selects a network interface named "LON1.”

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