20
PRO SWITCHING SYSTEM
2.3.10 O
PEN
C
OMMUNICATION
P
ORT
The Open Communication Port function lets you select one of the system’s
communication ports to which a modem or terminal is connected. Then, via the
PC, you can communicate directly with the connected device.
2.3.11 O
PEN
C
HANNELTO
M
ODEM
At the PC, you can open a channel to any online modem and communicate
directly with the modem for non-intrusive testing and diagnosis.
2.3.12 N
ETWORK
H
EALTH
C
HECK
To detect rack failures that preclude alarms, the PC runs a health check,
attempting to communicate with each rack. If a rack fails to respond, the PC
reports this failure.
Sites that are always online with the central PC are checked continuously. For
off-line sites, you can define a Health Check Schedule, specifying times when these
sites will be checked.
2.3.13 H
ISTORY
F
ILES
All alarms are written to the Session Alarm History file, which you may display
and/or clear at any time.
Alarms are also written to a separate ASCII log file on the hard disk. Another
ASCII log file maintains a record of important system events and operator actions.
2.3.14 W
ATCHDOG
T
IMER
The optional Watchdog Timer application switches users between two computer
systems, substituting a standby system for a failed system.
2.4 Control Communication
2.4.1 R
ACKSAND THE
M
ANAGEMENT
PC
AT
S
ITES
A Pro Switching System rack that is connected via its COMM IN port with the
management PC comprises a Pro Switching System site. The rack connected in this
way is the Primary Rack. At this site, other racks called Secondary Racks can
connect to the Primary Rack via their communication ports in daisy-chain fashion.
The location of the Management PC is referred to as the Primary Management
Site. The Management PC can communicate with up to 256 Pro Switching System
sites. This communication can be routed through the communication ports of the