[time-nuts] Even Seconds Pulse option (1PP2S), HP 58503B

[Gregory Beat]

A new resident arrived at the “Time Cave” this weekend, the HP/Symmetricom 58503B.  Just the plain front panel (4 LEDs) model, without Option 1 (VFD clock display).
Acquired in USA, cheaper than current Asian exporter.
https://accusrc.com/uploads/datasheets/4975_58503b.pdf

Supposedly stored in a closet since 2010 (verified by its diagnostic logs), the unit only had 2,000 hours of operation.
Today, it happily has a GPS Lock and is currently “re-learning” where the 1 PPS and 10 MHz outputs wandered (taming Lazarus).
—
One surprise, it has Option 2 (1PP2S) installed on its Rear Panel.

Option 002 : 1 PP2S (One-Pulse-Per-Two-Seconds) connector for outputting a pulse every other second, synchronized to the even seconds in GPS time. 
Pulses occur on even-numbered seconds (i.e., 2 seconds, 4 seconds, etc.).
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QUESTION: 
What Specific Applications would use this 1PP2S output regularly??

greg

Sent from iPhone 6s