Spectracom VelaSync 1232 User Manual page 243

50 and 98. The VelaSync uses the Control Function field to encode year data,
time synchronization status, and SBS time data. Table B-2 lists the Control Func-
tion 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.). Ele-
ments 60 through 63 contain the binary equivalent of year units. Elements 65 through
68 contain the binary 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 rate: 10 per second.
Position identifier rate: 1 per second.
Reference marker rate: 1 per 10 seconds.
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 iden-
tifier or reference marker is the on-time point for the succeeding code word.
VelaSync User's Manual
APPENDIX
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