Comparing Signal-Based and Time-Based Synchronization

Synchronizing multiple devices requires accurate timing for event synchronization and data correlation. NI-Sync achieves timing accuracy between devices using two synchronization methods: signal-based and time-based. In a signal-based application, clocks and trigger signals are shared directly between nodes that require synchronization. In a time-based application, nodes independently synchronize their individual clocks based on a common time source, usually an external timing reference like GPS.

Refer to the following table to weigh the pros and cons of using signal-based or time-based synchronization in an application:

Note Note   A combination of signal-based and time-based programming is often the best choice for complex system configurations with many different types of nodes in different locations.
Signal-BasedTime-Based
  • Nodes are less than 100 meters apart.
  • System has no access to an external time reference.
  • Nodes are physically connected using cables or switches.
  • System is in a closed environment without network access.
  • System requires higher precision synchronization.
  • System requires synchronization of a small number of nodes.
  • Nodes are more than 100 meters apart.
  • System has access to an external time reference, such as an IRIG generator or a GPS antenna.
  • Nodes are connected through a network (including through Ethernet).
  • System requires synchronization of a large number of nodes.
  • Nodes frequently change location.