1.  GENERAL


1.01   The  purpose of  the Maintenance  System for  the DMS  100
Family of Digital Multiplex Switching (DMS) systems is to provide
complete  maintenance  by detecting,  analyzing,  correcting  and
reporting errors in DMS software and hardware.


1.02   The Maintenance System consists  of a number of functional
areas,  each having  hardware  elements  and software  resources,
which interact  through internal  messages to  perform the  tasks
involved in automatic maintenance.


1.03    Each  functional  area,  referred  to  as  a  maintenance
sub-system (SS)  contains the software necessary  for maintaining
its  own  hardware.   The  functional  areas  correspond  to  the
hardware and  software components of  DMS which are  described in
NTP  297-1001-100.   Each  maintenance SS  locates and  diagnoses
errors occurring  within the area  of responsibility  assigned to
it.


1.04   The maintenance sub-systems  are accessible to maintenance
personnel  through the  Maintenance  and Administration  Position
(MAP) or other terminal devices such as TTY.   The MAP provides a
Man-Machine Interface (MMI) through its Visual Display Unit (VDU)
screen  and  keyboard.    The  VDU  screen  displays  DMS  status
information in  response to  requests from  maintenance personnel
entered  manually   via  the   VDU  keyboard.     Refer  to   NTP
297-1001-110  for  a detailed  description  of  the MAP  and  its
operating instructions.