Overview

Communicating with LonWorks® and CEA-709.1 Networks

Introduction

A multitude of Easylon products is designated to access the data of LonWorks or CEA-709.1 compatible networks for distributed, intelligent automation; especially the Easylon interfaces and Easylon software, such as the OPC Server or the RNI capability of the Easylon interfaces.

Design and scope of performance of the Easylon interfaces are designated to the highest demands. We attach great importance to

  • ability of use, especially in industrial applications,
  • support of current operating systems without cancelling the support of older versions,
  • support of current PC bus systems and latest technical developments,
  • usability in LonWorks networks either with or without LNS,
  • the needs of users that have to access these interfaces with their own applications,
  • the customers desire for products with most simple usability.

These are the reasons why each and any Easylon interface offers a variety of variants though they have a lot in common, as compiled in the following.
However, shouldn’t you be able to trace the solution you are looking for – just ask us. Maybe we already realized the solution for your problem for another customer in the past or it is already under development.

LonWorks and CEA-709.1

The ANSI/CEA-709.1 standard “Control Network Protocol Specification“ describes the LonTalk protocol underlying the LonWorks technology. Based on this specification and licensed by Echelon Corp. network nodes can be developed independent of the Neuron Chip otherwise mandatory. Gesytec is offering CEA-709.1 based products: the Interfaces+.  The plus is indicating that there is to be expected more than from a stand LonWorks node. The technology is as well described by the European standard EN 14908.

Interfaces+

Technically the “plus” products realize the control network functionality on chip different from the Neuron Chip. For the interfaces this means a separation into a physical and a logical part, also referred to as virtual network interface (VNI). With respect to a typical Easylon Interface+ card for a PC this means that the card implements protocol layers 1 and 2 of the interface while the PC realizes layers 3 to 7.
Several advantages arise from this:

  • The performance of modern PCs and servers can be used.
  • On the interface card a powerful processor and sufficient buffer can be used.
  • The PC receives all messages.
  • Time stamps can be set.
  • The PC sends messages with any source address.
  • The PC emulates several (currently up to 8) logical interfaces, each having a node-ID of its own.
  • Ordinary drivers are used to access the interface.
  • Several programs can access the interface hardware in parallel.
  • 16 bit programs as well as 32 bit or 64 bit programs can be used. 

In practice this means:

  • All PC applications previously used can be used further on without modifications.
  • Compatibility with Echelon interfaces.
  • Parallel transactions in MIP mode.
  • Up to eight applications can access the network in parallel. In addition to the normal applications network analysis and network management can be run.
  • A larger number of address table entries can be used.
  • There is an efficient hardware interface.
  • Any Easylon Interfaces+ is the hardware basis for the Easylon Analyzer.

Drivers for LonWorks Interfaces

Windows operating systems from Windows 2000 to the current ones are supported, for 32 bit and 64 bit systems. This refers as well to Windows CE. For some cards even older drivers for Windows 95 and 98, NT, ME or DOS are available. These, however, are no longer supported and are provided without warranty.

Using the drivers the user can assign driver names at will. This is as well advantageous with older systems and applications requiring a systematical naming when using several interfaces (LON1, LON2, …) as with distributed applications, which are accessed by the driver name, e.g. accessing remote systems via RNI. Then descriptive names can be used.

Linux drivers are provided too for most of the interfaces. They come in source code for different kernel versions.

Driver updates and versions for the latest operating systems can be downloaded any time from the support pages of the Gesytec web site. If you want others than the standard, feel free to ask.

MIP or NSI Firmware

To be able to operate as a network interface the Neuron Chip requires a special firmware. Two types are available: MIP and NSI. The NSI firmware is required if the interface is to be used by LNS based applications, e. g. a network management tool. This especially applies for older LNS versions up to 2.x. LNS 3.x version programs should use an Interface+, as these offer a better performance.

Interfaces running MIP firmware can be used for all other applications, e.g. the Easylon OPC Server M.

LonWoks Transceiver

In their standard version Easylon Interfaces come with a free topology TP/FT (FTT-10A) or FTX smart transceiver. Some interfaces are additionally available in standard variants with transformer coupled twisted pair transceiver (TP/XF-78 or TP/XF-1250). Depending on the interface type OEM variants with EIA-485 or Direct Connect (DC) transceiver can be realized. Most of the EIA-485 interfaces provide galvanic isolation.

For details concerning available transceivers and drivers, please refer to the technical specifications of the different interface devices.

Tools for Development and Commissioning

Several tools are provided to support setting up the interfaces for operation. Problems eventually arising can thus easily be tracked down. Developers appreciate that Easylon Interfaces support a debug mode, helpful with testing new applications.

EasyCheck, for instance, is a small, versatile utility for setup and diagnosis of Easylon interfaces. Basic tests and configurations, such as setting LonWorks address, mode and buffers, can easily be performed with EasyCheck. Communication tests can be performed by sending and receiving service pin messages. A higher level feature is scanning a domain for attached nodes. “Performance tests” will compare the speed of two interfaces. EasyCheck also shows the versions of all Easylon software installed on the PC.

Easylon IMaC, the Interface Management Center, offers everything you need for the configuration of LonWorks interfaces. Not only PC cards and external LonTalk adapters can be handled but as well the Easylon Remote Network Interface (Easylon RNI) and the Easylon IP Interface, the software interface to the LON IP channel.

Both programs are included in the Easylon Interface delivery.

WLDV32.DLL

The WLDV32.DLL, being part of the Easylon interface scope of delivery, offers a 32 bit driver interface for Windows operating systems including CE. Nowadays the program package also covers 64 bit applications. The WLDV32.DLL is as well available separately for use with interfaces from other manufacturers.

Remote Network Interface (RNI)

This software for remote access from a networked PC (LAN, Internet) via TCP/IP to the LON interface devices at a LonWorks or CEA-709.1 compatible network is part of the scope of delivery of the Easylon interfaces. This is the smartest solution to realize network management tasks in a distant network from your office PC. Find more details in the product description.