Echelon OpenLDV - Manual (Page 156)

148 Custom Network Interface
Overview
Echelon and other manufacturers provide a wide selection of network interfaces
for different L ON W ORKS channel types and for various computer requirements.
You can also create a custom OpenLDV compatible network interface.
Figure 38 shows a simplified view of how a custom network interface
communicates with an application:
• When a user uses a custom network interface for the first time or installs
custom network interface software, Windows installs the device driver
for the network interface and updates the Windows registry. In
addition, a custom network interface might use additional software for
device configuration (for example, you can use the L ON W ORKS Interfaces
application in the Windows Control Panel to configure Echelon devices).
• The application uses the OpenLDV API to communicate with both the
network interface and the L
ON
W
ORKS
network. For example, the
application calls the ldv_open() function to open the custom network
interface for communications.
• The OpenLDV API uses the entries in the Windows registry to map the
custom network interface’s logical name (what is presented to the user or
the application) to the physical device name (what is presented to the
device driver). This mapping is done whenever the custom network
interface is opened for communications.
Device
Driver
OpenLDV API
Application
Windows
Registry
Windows Computer
Custom Network Interface
To L ON W ORKS Network
Figure 38. A Custom Network Interface Communicates with an Application
This appendix describes how you can integrate a custom network interface driver
with the OpenLDV driver so that it is accessible from any OpenLDV application.
It does not describe how to develop the custom network interface hardware or
how to write the Windows device driver for the custom network interface.
Working with a Custom Network Interface
To make a custom Windows device driver accessible through the OpenLDV
interface, the driver must be a kernel-mode Windows Driver Foundation (or
Windows Driver Model) driver that provides standard create, read, write, and