User manual

TD990200-0ME

1 Introduction

Description

The Communication Processor Module provides either router or

gateway connectivity between ARCNET and Ethernet networks.

Usually in router/gateway applications, a desktop PC compatible

computer is dedicated to the task of executing the application

program from either a hard disk or floppy disk. On the PC

motherboard, two network interface modules are used to connect to

the two networks of interest. Using the Communication Processor

Module installed into a MOD HUB Modular Active Hub, this same

functionality can be provided in a compact and highly reliable

configuration.

The Communication Processor is a double-wide expansion module

that fits into the MOD HUB series of ARCNET Modular Active

Hubs. Once installed in a MOD HUB chassis, an ARCNET

connection is made through the chassis backplane. On the front

panel of the Communication Processor is an RJ-45 connector which

provides the 10BASE-T Ethernet connection.

Resident in the Communication Processor is an embedded DOS

computer with a solid-state flash disk capable of executing a DOS

based application program. This user supplied application program

could route packets between ARCNET and Ethernet networks that

utilize the same network layer or serve as a gateway between

different protocols used by the ARCNET and Ethernet networks.

For example, a popular transport layer for Ethernet is TCP/IP. In

order to route between ARCNET and Ethernet at the network layer

(IP), ARCNET would need to be operating a TCP/IP stack as well.

For all other situations where different higher level protocols are

involved, a gateway program would be needed to effect connectivity

between ARCNET and Ethernet. Either situation can be addressed

by the Communication Processor.

To provide ARCNET to Ethernet connectivity within a Metasys

system, the Embedded Metasys Ethernet Router was created by

installing the necessary application program onto the

Communication Processor. This product replaces the Metasys

Ethernet Router program which was originally designed to run on a

standard PC workstation. The program that executes the Metasys