[time-nuts] 60 Hz frequency and phase measurement

[Mark Sims]

In order to add Truetime XL-DC (and XLi support) to Lady Heather, I bought an XL-DC that happened to have the FTM-III module in it.  This module is designed to measure power line frequency for generating stations, etc,   It works well, but the minimum integration time is one second.   You can specify the integration interval (100,000 seconds (?) max.

It also does not measure voltage.    Heather can calculate xDEVs and MTIE from the data.  I had a nice run captured but lost it.   I'll do another run and post it when I am able to do another run.