2. TSEP Peter Plazotta, CEO of TSEP
David Courtney, Junior Developer from TSEP
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

3. Agenda Introduction to LXI LXI Standard 1.5 LXI Reference Design
IEEE 1588 Standard
Usage of 1588 in terms of LXI

4. Introduction to LXI
LXI is a standard which defines the behaviour of measuring devices in a network
2004 a non-profit consortium was founded by leading T&M companies
Today more than 50 T&M companies are represented
More than 3600 devices are LXI certified
All major players are represented in the LXI Consortium
Network is available on nearly every device, other bus systems are out dated (GPIB)

5. LXI Standard 1.5 Main goal:
Define the behaviour of measuring devices in a network
1.5 LXI Device Specification components:
Optional Extended Functions:
LXI HiSLIP
Physical Specifications
LXI Event Messaging
Programmatic Interface
LXI Event Logging
Web interface
LXI Clock Synchronization
Network Configuration
LXI Timestamped Data
mDNS for Device Discovery
LXI Wired Trigger Bus
LXI VXI-11 Discovery and Identification
LXI IPv6

6. LXI Reference Design Development: 2014: Start of development
2016: Release of the LXI Reference Design
Benefits:
Low cost solution for T&M companies to develop LXI conform devices
Cost-reduction in maintenance and further development (resides with the LXI Consortium)
Supports Windows and Linux
Support Capabilities:
VendorForum
Mantis bug tracing
To take advantage of the LXI Reference Design, you must be an LXI member

7. LXI Reference Design – LXI Standard
mDNS Module
Event Logging
Module
Event Messaging
HiSLIP Module & Server
Firmware
Interface
Network
Configuration
Core Framework
LXI Device Specification 2016 Modules
Optional Extended Functions
Excluded Extended Functions
Coming Soon to the Reference Design
VXI-11
Module
Clock
Synchronisation
Module
Timestamped
Data
Module
Wired
Trigger Bus
Module

8. IEEE 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.
1985: NTP Protocol published as RFC 985 by David L. Mills which achieved accuracies around a microsecond (1x10-6 sec)
1990: a group around John C. Eidson was created to improve the NTP protocol
2000: John C. Eidson published there results
2002: IEEE Standard was published as a result of John C. Eidson investigations which shall achieve accuracies within sub micro seconds.
2008: Current standard IEEE was published
What has happened since:
The team around John C. Eidson is continuing to improve the standard
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

9. IEEE 1588 – Problems to solve
Major issues to synchronize devices:
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.
Ethernet is a non deterministic connection, therefore the transmission times vary
Runtimes within a device (network stacks, drivers etc.) are also not deterministic, as „preemtive scheduling“ can interrupt any process at any time.
As a transfer medium a consumer product shall be used (network chips)

10. Synchronization
T1: Master sends periodically Sync messages (containing send time)
T2: Slave receives Sync message
T3: Slave issues Delay Request messages
Master responds with a Delay Response message
T4: Slave receives Delay Response which contains the receive time of the previously sent Delay Request message.

11. How can we use 1588 in terms of LXI?
Facts:
Trigger runtime per meter: 4ns
With a precision of 20ns via 1588, measurements are more precise than any trigger via >5m cables.
Use-cases:
Synchronised devices can fullfill high precision measuring with distance being irrelevant
Run measuring sequences based on time sequences instead of triggers
Offline evaluation and correlation of measuring data
LXI:
LXI Clock Synchronization coming soon to the LXI Reference Design (planed June 2017)
LXI provides LAN Event Messages which enhance the advantages of 1588 by using time stamps.

12. More questions, come and visit us!
TSEP
Technical Software Engineering Plazotta
Hopfenstr. 30
85283 Wolnzach, Germany
Phone:
Telefax: