ACC Programmer's Reference Guide

Chapter 3 79
ZCOM Tables and Data Structures
Interface Table
driver and the interface card (via “zmon restart”).
ISCHDL - Scheduler event flags
The scheduler uses this word to store the event flags that control the
state of the backplane.
Figure 3-6 Scheduler Event Flags ISCHDL
ITCNTR - Interface terminal counter
The terminal counter is the actual number of t erminals defined on this
Mux interface card.
IFRTRY - Reset retry count
This is used to count the number of times the Mux interface has been
reset due to a b ackplane timeout, or firmware failure. It is incremented
by ZMON each time the Mux card is reset by a request from the DAM. If
it reaches an unsatisfactory level, the Mux card will be disabled (set
down) by ZMON.
The driver will decrement t he retry count if it is not zero after every 30
successful status $STDT replies (i.e., every 5 minutes). If an unstable
Mux interface fails and restarts too often, the ZCOM subsystem will
markitas“down”andstopusingit.
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AC ST
AC -
ST -
Driver currently active
Card has sent status transfer request ($STDT)
NB -
NB
Driver cannot get any free system buffers
PA - Pause after current event
PA