The VersaSync uses the Control Function field to encode year data, time syn-
chronization 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.). 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 sig-
nificant 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 identifier or ref-
erence marker is the on-time point for the succeeding code word.
338 VersaSync User Manual
APPENDIX