ptp time sync mode - what is the used time Coordinated System? UTC?

[salsabeel-imagry]

• Sensor: RS-Ruby-128
• what I did
  • Configured the time synchronization source to the lidar to "PTP-E2E-4L"
  • Configured the ptp-master to send the system time in UTC (using ptp4l linux cmd)
  • Read the MSOP Header Data and extract the "Timestamp" field
  • Read the DIFOP packet and extract "Time Sync Info" and "Time" fields
• What I get:
  • Time_Sync_Mode byte donated that E2E protocol is used
  • Time_Sync_State byte denoted that "Synchronization successful"
• The issue
  • When parsing the Timestamp fields (from both MSOP header and DIFOP packet) the output data time shows 37 seconds difference from the UTC
  • i.e. lidar data time is 37 seconds behind the UTC time
• My question:
  • Which Coordinated System does it use in the lidar? May it use TAI and not UTC?
  • Is there any explanation why the 37-second diff?