TSEP
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Peter Plazotta, CEO of TSEP
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David Courtney, Junior Developer from TSEP
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About TSEP
• >20 staff members (engineers, software developers, software
developer trainees)
• Development of complete software solutions for Measuring Devices
• Development of test systems for different companies, used world wide
(Germany, US, China, Japan, Singapore)
• System software development for customers
• LXI Member
- Technical Software Engineering Plazotta
Agenda
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Introduction to LXI
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LXI Standard 1.5
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LXI Reference Design
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IEEE 1588 Standard
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Usage of 1588 in terms of LXI
- Technical Software Engineering Plazotta
Introduction to LXI
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LXI is a standard which defines the behaviour of
measuring devices in a network
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2004 a non-profit consortium was founded by
leading T&M companies
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Today more than 50 T&M companies are
represented
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More than 3600 devices are LXI certified
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All major players are represented in the LXI
Consortium
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Network is available on nearly every device, other
bus systems are out dated (GPIB)
- Technical Software Engineering Plazotta
LXI Standard 1.5
Main goal:
Define the behaviour of measuring devices in a network
1.5 LXI Device Specification 2016
components:
 Physical Specifications
 Programmatic Interface
 Web interface
 Network Configuration
 mDNS for Device Discovery
Optional Extended Functions:
 LXI HiSLIP
 LXI Event Messaging
 LXI Event Logging
 LXI Clock Synchronization
 LXI Timestamped Data
 LXI Wired Trigger Bus
 LXI VXI-11 Discovery and Identification
 LXI IPv6
- Technical Software Engineering Plazotta
LXI Reference Design
Development:
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2014: Start of development
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2016: Release of the LXI Reference Design
Benefits:
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Low cost solution for T&M companies to develop LXI conform devices
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Cost-reduction in maintenance and further development (resides with the
LXI Consortium)
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Supports Windows and Linux
Support Capabilities:
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VendorForum
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Mantis bug tracing
To take advantage of the LXI Reference Design, you must be an LXI member
- Technical Software Engineering Plazotta
LXI Reference Design – LXI Standard
Network
Configuration
Module
Firmware
Interface
Module
mDNS
Module
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LXI Device Specification 2016 Modules
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Optional Extended Functions
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Excluded Extended Functions
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Coming Soon to the Reference Design
Core
Framework
Event
Logging
Module
VXI-11
Module
HiSLIP
Module &
Server
Event
Messaging
Module
Clock
Synchronisation
Module
- Technical Software Engineering Plazotta
Timestamped
Data
Module
Wired
Trigger Bus
Module
IEEE 1588 - Introduction
Aim of IEEE 1588 is to dstribute the time of a very exact time source such as an
atomic clock or GPS to one or several devices in a network.
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1985: NTP Protocol published as RFC 985 by David L. Mills which achieved
accuracies around a microsecond (1x10-6 sec)
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1990: a group around John C. Eidson was created to improve the NTP protocol
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2000: John C. Eidson published there results
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2002: IEEE Standard 1588-2002 was published as a result of John C. Eidson
investigations which shall achieve accuracies within sub micro seconds.
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2008: Current standard IEEE 1588-2008 was published
What has happened since:
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The team around John C. Eidson is continuing to improve the standard
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But also a coaltion of companies and institutions (CERN, GSI Helmholtz-Center,
National Instruments) devloped 2011 the „White Rabbit Standard“ which was
derived from IEEE 1588-2008
- Technical Software Engineering Plazotta
IEEE 1588 – Problems to solve
Major issues to synchronize devices:
1.
Each device is implemented as a counter which counts the cycles and
calculates the time via the freuquency of the time source. These cycles vary
from device to device.
2.
Ethernet is a non deterministic connection, therefore the transmission times
vary
3.
Runtimes within a device (network stacks, drivers etc.) are also not
deterministic, as „preemtive scheduling“ can interrupt any process at any
time.
4.
As a transfer medium a consumer product shall be used (network chips)
- Technical Software Engineering Plazotta
1588 - Synchronization
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T1: Master sends periodically Sync messages (containing send time)
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T2: Slave receives Sync message
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T3: Slave issues Delay Request messages
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Master responds with a Delay Response message
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T4: Slave receives Delay Response which contains the receive time of the
previously sent Delay Request message.
- Technical Software Engineering Plazotta
How can we use 1588 in terms of LXI?
Facts:
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Trigger runtime per meter: 4ns
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With a precision of 20ns via 1588, measurements are more precise than any trigger
via >5m cables.
Use-cases:
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Synchronised devices can fullfill high precision measuring with distance being
irrelevant
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Run measuring sequences based on time sequences instead of triggers
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Offline evaluation and correlation of measuring data
LXI:
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LXI Clock Synchronization coming soon to the LXI Reference Design (planed June
2017)
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LXI provides LAN Event Messages which enhance the advantages of 1588 by using
time stamps.
- Technical Software Engineering Plazotta
More questions, come and visit us!
TSEP
Technical Software Engineering Plazotta
Hopfenstr. 30
85283 Wolnzach, Germany
Phone: +49 8442 955457
Telefax: +49 8444 9559389
- Technical Software Engineering Plazotta