Orolia Spectracom VelaSync 1232, User Manual

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Time frame : 10 seconds.
Code Digit Weighting :
Binary Coded Decimal time of year.
Code world - 26 binary digits.
Tens of seconds, minutes, hours, and days.
Recycles yearly.
Code Word Structure : BCD word tens of seconds digits begin at index count 6. Bin-
ary 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 resolution. Least significant digit occurs first.
Control Functions : IRIG formats reserve a set of elements known as Control Func-
tions (CF) for the encoding of various control, identification, or other special purpose
functions. IRIG E has 45 Control Functions located between elements 50 and 98.
The VelaSync 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.
VelaSync 1232 User Manual 229
APPENDIX