[Linuxptp-users] Can phc2sys sync two physical clocks?

[John H. <jhu...@no...>]

As I understand it the phc2sys package is generally responsible for 
synchronizing a physical clock to the system time or vice versa.  Is it 
possible to use the package to synchronize two physical clocks?

In my case I'm looking to take wall time as determined by a NIC that 
supports hardware timestamping using the ptp4l package and write that 
time to a DIO card that has its own internal clock.  We were using a 
previous version of the DIO card which had an ethernet input and was 
capable of synchronizing itself to PTP. The new version lacks that 
feature.  In case it helps the card in question is a Spectracom TSync 
PCIe; we are using the cards input time stamping, and output match time 
features.

My hope is that you, who are more knowledgeable on time than I, might 
have suggestions on the best way to synchronize the card's time with the 
incoming PTP time.  Is my best bet to read the system time via 
std::chrono::system_clock::now() and then write that time to my DIO 
card.  Is there some way to read the current time directly from 
/dev/ptp0?  Is there an easy way to extend phc2sys to write the time to 
my DIO card?

Thanks in advance for any suggestions.

-- 
-john

To be or not to be, that is the question
                 2b || !2b
(0b10)*(0b1100010) || !(0b10)*(0b1100010)
         0b11000100 || !0b11000100
         0b11000100 ||  0b00111011
                0b11111111
255, that is the answer.