Irig E Output - Spectracom SecureSync 1200 User Reference Manual

5.5.4

IRIG E Output

The IRIG E code contains the Binary Coded Decimal (BCD) time of year and Control Functions.
The figure IRIG E Time Code Description illustrates the IRIG E data structure. The BCD time of
year provides the day of year, 1-366, and time of day to tens of seconds. The hour of the day
is expressed in 24 hour format. The Control Function field includes a time synchronization
status bit, year information and SBS time of day.
Time frame : 10 seconds.
Code Digit Weighting :
Code Word Structure : BCD word tens of seconds digits begin at index count 6. Binary
coded elements occur between position identifier elements P0 and P5 (3 for seconds, 7
for minutes, 6 for hours, and 10 for days) until the code word is complete. An index
marker occurs between decimal digits in each group to provide separation for visual res
olution. Least significant digit occurs first.
Control Functions : IRIG formats reserve a set of elements known as Control Functions
(CF) for the encoding of various control, identification, or other special purpose func
tions. IRIG E has 45 Control Functions located between elements 50 and 98. The
SecureSync uses the Control Function field to encode year data, time synchronization
status, and SBS time data. Table B-2 lists the Control Function Field and each element's
function.
Element 55 is the time synchronization status bit. Element 55 is a Binary 1 when the front panel
time synchronization lamp is green, and a Binary 0 when the lamp is red.
Year information consists of the last two digits of the current year (i.e. 98, 99, etc.). Elements 60
through 63 contain the binary equivalent of year units. Elements 65 through 68 contain the bin
ary equivalent of tens of years. In keeping with IRIG formats, the least significant bit occurs first.
Elements 80 through 97 are encoded with the Straight Binary Seconds (SBS) time data. The
SBS time data is incremented in 10-second steps and recycles every 24 hours.
Pulse rates:
SecureSync User Reference Guide
Binary Coded Decimal time of year.
Code world - 26 binary digits.
Tens of seconds, minutes, hours, and days.
Recycles yearly.
APPENDIX
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