E: Time Code Formats; Overview; Irig; Introduction - Symmetricom XLi User Manual

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E: Time Code Formats

The following section provides a summary description of the three time code types used by the XLi. The
definitive IRIG time code specification, the Range Commanders Council's IRIG Serial Time Code
Formats, IRIG Standard 200-04, is available on the Web at:
https://wsmrc2vger.wsmr.army.mil/rcc/manuals/200-04/TT-45.pdf
In addition to the IRIG Standard 200-04 document,
extends the Range Commanders Council document with additional fields. These fields include,
leap second information, Daylight Saving Time information, binary coded decimal seconds and
time quality information. The IEEE Std 1344-1995 document is purchased at
. The same document is summarized at the following link:
standards.ieee.org/
http://standards.ieee.org/reading/ieee/std_public/description/relaying/1344-1995_desc.html

Overview

Please refer to the Input and Output specifications in the front of the manual for details regarding the
voltage amplitudes / modulation ratios of the following time codes provided or used by the Model XLi.

IRIG

Introduction

The document 200-04 "IRIG STANDARD TIME FORMATS" by the Telecommunications Working Group,
Inter range Instrumentation Group, Range Commanders Council describes IRIG-B and IRIG-A time
codes.
The standard time formats of IRIG codes were designed for use in missile, satellite and space research
programs. Use of these codes facilitates efficient interchange of test data. These formats are suitable
for recording on magnetic tape, oscillographs, film and for real time transmission in both automatic and
manual data reduction. IRIG-B from the Model XLi is suitable for remote display driving, magnetic tape
recording and many other uses. IRIG codes, in the strict sense, encode Coordinated Universal Time
(UTC) in 24 hour format and not local time. Nonetheless, this instrument can encode UTC or local time
in either 24 or 12 hour formats.

IRIG Code Format

Reference "IRIG Standard Format A" on page
formats of IRIG-B and IRIG-A are divided into three segments. The first segment encodes time of year
in binary coded decimal (BCD) notation. The second segment encodes control functions. This segment
is generally available for data of the user's choice. In the IRIG-B code output of Model XLi, this segment
encodes worst case time error flags as explained below. The IRIG-A output from Model XLi does not
include control functions. The third segment sometimes encodes time of day in straight binary seconds
(SBS) notation. Both IRIG-B and IRIG-A encode SBS on the Model XLi.
XLi Time & Frequency System
XLi-man, Issue 8, 6/17/2008, Rev. H
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
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290. The level shifted, pulse width modulated, serial
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the "IEEE Std space 1344-1995" document
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