NTI M-Module
NTI M-Module
Abstract.
This paper provides a comprehensive overview of our
Network Time Interface (NTI) M-Module, which facilitates
high-accuracy time distribution in LAN-based distributed real-time
systems. Built around our custom UTCSU VLSI chip, it actually hosts
all the hardware support required for interval-based external clock
synchronization: A high-resolution state- and rate-adjustable clock,
local accuracy intervals, interfaces to GPS receivers, and various
timestamping features. Maximum network controller and CPU
independence ensures that the NTI can be employed in virtually any
COTS-based system with M-Module interface. Our experimental
evaluation shows that time distribution with µs-accuracy is
possible even in Ethernet-based system architectures, provided that
the available configuration parameters are carefully chosen to cope
with the various hidden sources of timing uncertainty.
Abstract.
This paper reports on the experimental evaluation of the Network
Time Interface (NTI) M-Module developed in our SynUTC-project at
TU Vienna. Designed for COTS-based distributed systems, the NTI
provides all hardware-related features for high-accuracy interval-based
external clock synchronization, like a high-resolution rate- and
state-adjustable clock, local accuracy intervals, interfaces to GPS
receivers, and various timestamping features. The evaluation results
shows that the NTI enables GPS time distribution with µs-accuracy
even in Ethernet-based systems. However, the available configuration
parameters must be carefully chosen ---and experimentally verified---
in order to cope with the various hidden sources of timing uncertainty.
Abstract.
This report documents the final version of the NTI-driver, a pSOS device
driver for the i82596 Ethernet-coprocessor that also supports our Network
Time Interface (NTI) M-Module for clock synchronization. Its remaining
chapters are organized as follows:
The second chapter describes the environment of the NTI-driver, which
consist of its clients and the underlying hardware components.
Chapter three is a presentation of the NTI-driver itself. It contains a
detailed description of its interfaces to the environment and its internal
structure. The different layers and their interactions are also explained
in detail.
Chapter four is a programmer's reference. Naturally, this chapter is rather
voluminous. It contains a detailed description of the NTI-driver structure
from the programmer's point of view (interaction of the functions, file
structure of the NTI-driver, which file keeps which functions etc.) and
lists all the constants, data structures, global variables and functions
in exhaustive detail.
Chapter five finally contains usage issues, along with a brief description
of a sample application developed for experimental evaluation of the resulting
system's timestamping accuracy.
The appendix contains a list of the used abbreviations, the bibliography and
an index.
Abstract.
This report briefly describes the functions provided for incorporating our
Network Time Interface M-Module (NTI) into a MVME-162-based pSOS system with
the i82596 NTI Device-Driver. Implemented as a number of C header and source files,
our NTI-Handler provides all functionality required for installation, interrupt
handling and usage of multiple NTIs plugged on a MEN A203 or AcQ i6360
VME carrier board.
Abstract (in German).
Die vorliegende Arbeit beschreibt die Prototypentwicklung eines
Uhrensynchronisationsmoduls mit Hilfe eines CPLDs und die
Optimierungsverfahren, die notwendig waren, um das Design in
beschränkter Zeit und mit hoher Integrationsdichte realisieren
zu können.
Abstract.
This paper provides a description of our Network Time Interface M-Module
(NTI) supporting very-high accuracy external clock synchronization by
hardware. The NTI is built around our custom Coordinated Universal Time
Synchronization Unit (UTCSU), which contains most of the hardware support
required for interval-based clock validation: A state and rate adjustable
clock device, automatically maintained accuracy intervals, interfaces to
GPS receivers, and various timestamping features. Designed for maximum network
controller and CPU independence, our NTI provides a turn-key solution for
adding high-resolution synchronized clocks to distributed real-time systems
built upon hardware with M-Module interfaces.
Abstract (in German).
Eine im Rahmen des wissenschaftlichen Projekts SynUTC an der
TU Wien entwickelte Hard- und Software erlaubt es, die Knoten eines
netzwerkgekoppelten Mikroprozessorsystems mit im µs-Bereich
zueinander und auf Weltzeit synchronisierten Uhren auszurüsten.
Wohldefinierte theoretische Grundlagen, exzellente
Fehlertoleranzeigenschaften sowie weitgehende Flexibilität
bezüglich der zugrundeliegenden Hardware und Netzwerktechnologie
sind weitere Charakteristika der entwickelten "enabling technology",
mit deren Hilfe völlig neue Anwendungsgebiete erschlossen werden
können.
Abstract (in German).
Das vorliegende Dokument fasst kurz die Eigenschaften
eines Kabel-Fehlerortungssystems zusammen, das mit den Ergebnissen
unseres Forschungsprojektes SynUTC realisiert werden kann. Bei dieser
Darstellung wird insbesondere versucht, auf jene Aspekte hinzuweisen,
die nach derzeitigem Wissensstand patentrechtlichen
Neuigkeitscharakter haben könnten.
Abstract.
The NTSU has to support real-time transmission in order to synchronize
distributed clocks and to build a LAN capable for real-time communication.
It is built upon the LANCE 82596 LAN-coprocessor from INTEL piggybacked on
a VME 162-512A carrier-board. For testing the driver software, it is necessary
to develop a simulated environment, where the user/programmer can verify the
behaviour of the driver under different circumstances and environmental
conditions independent of the underlying hardware. Thus, such an environment
has to simulate not only the hardware (NTSU and LAN), but also the application
software, which is situated on top of the driver and uses its services for
communication via the LAN. The driver can be tested either completely embedded
in the simulation software, or just the application half. A second version of
the driver tailored for the M68360 LAN-Coprocessor from Motorola is also under
development.
