Protogate Freeway 3414, Hardware Maintenance Manual, Page: 19 / 72

1: Introduction
DC 900-2031A 19
Protogate does not recommend replacing the CPU board or single power supply (3414
only) in the field, therefore they are not documented in this manual. Replacing the CPU
board requires multiple cable connections and specific BIOS settings. To replace the
single power supply, you must remove most of the internal components. Because of this
complexity, it is recommended that these two items be replaced only at the repair depot
or at the Protogate factory.
1.2 Preventative Maintenance
The following are the recommended preventative maintenance actions for the Freeway:
1. Check and clean the fan filter every three months as described in Section 2.4 on
page 33 .
2. Replace the CPU CMOS battery every 5 to 10 years as described in Section 4.5
on page 52 .
1.3 Freeway Overview
The Freeway enables client applications to access specialized wide-area networks
(WANs). It is user programmable and communicates in real time. It provides multiple
data links and a variety of network services to LAN-based clients in financial, defense,
telecommunications, and process-control applications. To maintain high data through-
put, the Freeway uses a multi-processor architecture to support the LAN and WAN ser-
vices. Figure 1–1 shows a block diagram of the Freeway configuration in a typical
application.
The LAN interface is managed by the server processor (on the CPU board). This single-
board computer uses the FreeBSD operating system to provide layered services needed
by the Freeway.
The WAN interface is managed by one or more intelligent communications processors
(ICPs). These boards communicate with the CPU board through a Peripheral Compo-