Irig B Output - Spectracom SecureSync User Reference Manual

The Spectracom IRIG formats use the control functions for BCD year information and a Time Sync
Status bit and in format E the control functions are used for straight binary seconds (SBS). Refer to
individual IRIG Time Code description figures and text. IRIG Standard 200-98 format B had 27 con-
trol bits and format E had 45 bits for control functions. These control bits could be used for any use
and there was no defined function. Spectracom used the control function element at index count 55
as the TIME SYNC STATUS and the sub-frame after position identifiers P6 and P7 as the year
info and for format E the sub-frame after P8 and P9 for the straight binary seconds (SBS). The pos-
ition of the BCD year information does not conform to the newer IRIG Standard 200-04. IRIG
Standard 200-04 incorporated the year information after P5 and reduced the allocated control bits
to 18 for format B and 36 for format E.
NOTE –
identifier having a positive pulse width equal to 0.8 of the reciprocal of the bit rate, a
binary one (1) having a positive pulse width equal to 0.5 of the reciprocal of the bit
rate and a binary zero (0) having a positive pulse width equal to 0.2 of the reciprocal
of the bite rate.
SecureSync can provide IRIG A, IRIG B, IRIG E and IRIG G code in amplitude modulated (AM) or
pulse width coded (TTL) formats. A signature control feature may be enabled for any IRIG output.
Signature control removes the modulation code when a Time Sync Alarm is asserted.
8.2.2

IRIG B Output

The IRIG B Time Code description follows.
SecureSync User Reference Guide
DCLS is DC Level Shifted output, pulse width modulated with a position
APPENDIX
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