Linux

• Each interface which has MultiSense camera connected will need a standalone phc2sys service.

• The following is an example phc2sys command we use for synchronizing cameras on a specific interface

  • phc2sys -c <interface> -S 1 -s CLOCK_REALTIME -l7 -O 0 -m

    • -c <interface> sets the sink clock to be the device <interface>, which is populated with the connected interfaces.

    • -S 1 indicates that the step threshold is 1 second, meaning that if the network interface’s clock lags the system clock by more than a second, then it will be adjusted via a discontinuous clock step (rather than increasing the frequency of the hardware clock to gradually catch up).

    • -s CLOCK_REALTIME sets the source clock to be the system’s realtime clock.

    • -l7 enables debug logging.

    • -O 0 indicates that the offset between the source and sink clocks is 0 seconds (meaning, they should be the same time).

    • -m enables printing to the standard output.

  • For each of the phc2sys instances, we need a corresponding ptp4l service running on the host system.

    • We run with the following configuration

      • ptp4l -q -f ptp4l.cfg

      • Here, -q disables logging to the system log

      • -f ptp4l.cfg loads the rest of the config for a specific interface.

      • Here is an example of a ptp4l.cfg file configured for the enp5s0 interface.

[global]
# Ensures that the interface can only set other clocks, and cannot have its clock set by the host machine.
masterOnly  1
# More logging.
verbose             1
# Debug logging.
logging_level       7
# Specifies the time-to-live limit for multicast messages, ensuring that they can hop at most 2 subnets.
# Update depending on your network topology
udp_ttl             2

# This line changes depending on the network interface.
[enp5s0]