Model: MC-1-DE
Doc Ref. No:-m05dom102
Issue No:-00
Page 49 of 76
User’s Manual
9.2 Timing Output – IRIG-B
9.2.1 Introduction
This section should help you with understanding, choosing and connecting the correct output from the
GPS TIME SYNC UNIT MC-1-DE to synchronize equipments, such as relays, meters etc. Often,
questions arise about how output port should be connected, and how to connect cabling between
model MC-1-DE and the relay. Certain protective relays or digital fault recorders may use a different
style connector than available at model MC-1-DE outputs. This section will help to answer some
common questions, like which type of cabling should be used? Coaxial or a twisted pair etc.
The steps involved in getting your devices synchronized to the model MC-1-DE are fairly simple and
should not take long to complete. To expedite the process, make sure that you know:
1. The type of timing signal each piece of equipment requires, and
2. How to enable the equipment to receive the timing signal.
Various methods are used to configure equipment for IRIG-B including setting a physical jumper, or
setup program. Some equipment can auto detect the timing signal, so that nothing else is required
other than connecting the cable.
9.2.2 Time Code Output:
This section will describe IRIG-B Time Code also availability of the same in model MC-1-DE also con-
figuration for the same. GPS TIME SYNC UNIT MC-1-DE can generate different no of digital as well
as analog signals as described in this section.
9.2.2.1 Standard IRIG-B Output:
As per figure 2, GPS TIME SYNC UNIT MC-1-DE model has three, BNC, connectors that supply tim-
ing signals to external equipment. Two of output is designed for IRIG-B AM/DCLS and other for 1PPS.
NOTE: On the Front plate of model MC-1-DE IRIG-B DCLS time code signal is referred as IRIG-B
TTL.
9.2.2.2 Abstract of IRIG-B Time Code:
The transmission of coded timing signals began to take on widespread importance in the early 1950’s.
Especially the US missile and space programs were the forces behind the development of these time
codes. The definition of time code formats was completely arbitrary and left to the individual ideas of
each design engineer due to that hundreds of different time codes were formed, some of which were
standardized by the "Inter Range Instrumentation Group" (IRIG) in the early 60’s.
Today electronic systems such as communication system, data handling systems require time of
day/year for data correlation of data with time. IRIG-B is a serial time code that occurs once per
second and depending protocol it contains day of year, hour, minute, seconds, year and other impor-
tant information. Except these, "IRIG Time Code” other format like IEEE1344 code which is an IRIG
coded extended by information for time zone, leap second, etc.
IRIG-B fully described in IRIG Standard 200-04, released by RANGE COMMANDERS COUNCIL of
the US Army White Sands Missile Range. IRIG-B format standard allows number of configurations
that designated as IRIG-Bxyz, where x indicates the modulation technique, y indicates carrier signal
frequency and z indicates data contained in the signal. IRIG-B time code consists of 100 bits out of 74
bit used for time, date, and control functions. The 74 time code bits divided into:
30 bits for BCD value of Seconds, Minutes, Hours, and current day of the year
