B
bitrex
Guest
On 7/21/2022 10:12 AM, bitrex wrote:
At minimum it likely won\'t scale very well. Why implicitly discourage
one\'s customers from buying only a limited number of units
On 7/21/2022 4:33 AM, John Walliker wrote:
On Thursday, 21 July 2022 at 07:49:43 UTC+1, whit3rd wrote:
On Wednesday, July 20, 2022 at 4:21:08 PM UTC-7, John Larkin wrote:
Suppose I have several rackmount boxes and each has a BNC connector on
the back. Each of them has an open-drain mosfet, a weak pullup, and a
lowpass filtered schmitt gate back into our FPGA.
I can daisy-chain several boxes with BNC cables and tees.
Each box has a 40 MHz VCXO and I want to phase-lock them, or at least
time-align them to always be the same within a few microseconds,
longterm.
If you can tolerate \'a few microseconds\' on a 40 MHz signal, that\'s
not a phase-lock
problem, it\'s a frequency-lock problem. Why not just run an up/down
counter
to generate a correction voltage for each non-leading VCO?
If you have an ethernet interface to each unit then Precision Time
Protocol
should do exactly what you want.
https://en.wikipedia.org/wiki/Precision_Time_Protocol
John
Yeah, that sounds like the ticket to me also. Trying to use each box\'s
system clock for purposes of keeping \"user-space\" tasks in sync across
boxes makes me uncomfortable, sounds like a srs hack.
At minimum it likely won\'t scale very well. Why implicitly discourage
one\'s customers from buying only a limited number of units