Spectracom PRISMA VelaSync User Manual page 226

APPENDIX
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:
Element identification: The "on time" reference point for all elements is the pulse leading
edge.
Index marker (Binary 0 or uncoded element): 20 millisecond duration.
Code digit (Binary 1): 50 millisecond duration.
Position identifier: 80 millisecond duration.
Reference marker: 80 millisecond duration, 1 per 10 seconds. The reference marker
appears as two consecutive position identifiers. The second position identifier or ref-
erence marker is the on-time point for the succeeding code word.
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Element rate: 10 per second.
Position identifier rate: 1 per second.
Reference marker rate: 1 per 10 seconds.
VelaSync User's Manual