AiVibePrecision Time Protocol (PTP, IEEE 1588)
The Precision Time Protocol, defined in IEEE 1588, synchronises clocks across a network with sub-microsecond accuracy by exchanging timestamped messages and measuring path delays, typically using hardware timestamping.
PTP selects a grandmaster clock, usually the most accurate source available such as a GNSS-disciplined clock, using the best master clock algorithm. The grandmaster sends synchronisation messages, and devices exchange delay request and response messages to calculate the network path delay and their own offset. Boundary clocks in switches synchronise to an upstream master and serve downstream devices, while transparent clocks correct timestamps for the time frames spend inside the switch. Hardware timestamping at the network interface is key to high accuracy.
Accurate time is needed for sequence-of-events recording, correlating data from distributed sensors and historians, motion coordination, power system protection and synchrophasors, telecommunications and financial trading. Profiles include IEEE 802.1AS for Time-Sensitive Networking, the IEC 61850-9-3 power utility profile and IEEE C37.238 for power systems, and CIP Sync applies IEEE 1588 to EtherNet/IP networks.
Accuracy depends on every device in the path supporting PTP appropriately, on network load and path asymmetry, and on the quality of the grandmaster. The Network Time Protocol (NTP) is simpler and sufficient for logging with millisecond-level accuracy, while PTP is used where tighter synchronisation is needed. Redundant grandmasters, monitoring of synchronisation state and protection against spoofing of time sources improve resilience.
Key points
- IEEE 1588 protocol for sub-microsecond clock synchronisation
- The best master clock algorithm selects the grandmaster
- Boundary and transparent clocks maintain accuracy across switches
- Profiles include IEEE 802.1AS, IEC 61850-9-3 and IEEE C37.238
- Hardware timestamping is key to high accuracy
Where AiVibe comes in
AiAmbA IoT is AiVibe's edge protocol layer: it discovers devices and normalises industrial signals, with supported protocols including Siemens S7, Mitsubishi MC, Delta Modbus, OPC UA and MQTT, and driver availability confirmed per installation. Writes to machines are deny-by-default.