ACC Utilities Reference Guide

WATCH - Mux Shutdown Feature
Overview
Chapter 10200
Overview
The Dual Interface Configurations allow two ACC interface cards to be
connected to a one mux panel/cable. In order for the interface ports to be
accessed, they must be configured as LOOPBACK from one interface
card, and as RS232, X.21 (or whatever is appropriate) from the other
interface card.
In order to pass control of a given interface port from one mux card to the
other, all of the activity on the given port must be terminated, the port
must then be put into LOOPBACK mode by the interface card that is
relinquishing control and into the appropriate (RS232, X.21, etc.) mode
by the interface card that is taking over control.
In the case that the system that is currently controlling the mux panel or
cable panics, there must be a way for the distressed system to relinquish
control of the panel/cable. This is done by using the watch daemon and by
using the MONITOR protocol module. The watch daemon sends
heartbeats to the MONITOR protocol module. In the case that the
protocol module on the card no longer receives a heartbeat from the
daemon, it halts the card and places all ports into tri-state (loopback)
mode.
It is suggested that the watch feature always be used when dual
interface configurations are used.
The watch daemon logs its messages to the ZCOM message log. Refer to
the ACC Error Guide for its error messages.