160 Options List
C.16.9 Option 28 Specific RS-232 Commands
The following symbols and syntax are used throughout the RS-232 Commands listing and are
repeated here for emphasis:
C
Shorthand for Carriage–Return, Line–Feed.
“A” Channel A.
“B” Channel B.
“U” UTC Time, Channel A (or B).
“L” Local Time, Channel A (or B).
Fourteen (14) new RS-232 commands are available with Option 28. The following conventions
apply to all RS-232 communications:
• Phase angle, in all messages, is defined as zero (or 360) for the positive-going zero crossing
coincident with 1 PPS-GPS, and is scaled between zero and 360 degrees. Phase angle increases
with frequency below nominal (50 or 60 Hz) and decreases with frequency above nominal; in
other words, if the zero crossing occurs just after 1 PPS-GPS, the phase angle will be just
above zero, and if the zero crossing occurs just prior to 1 PPS-GPS, phase angle will be just
under 360.
• Time deviation decreases (becomes more negative) with frequency below nominal, and in-
creases (becomes more positive) with frequency above nominal.