Synchronization and Time recording
124 A4354-2.2 HBM: public PMX
9.2 External synchronous measurement
acquisition via an NTP server in the
network
If synchronous measurements are to be performed by
different measurement systems, an external master is
required for synchronous acquisition.
Each PMX module has an NTP time that can be set by
an external NTP server. The NTP time is distributed to all
the modules over the Ethernet (TCP/IP) connection.
The PMX modules now transfer their measured values
with the counter signal and NTP time. The DAQ systems
can then use this information to synchronously acquire
the measured values of all the devices.
When operating the PMX and other devices, it is then
possible to achieve accuracies of 1 ms and better. But
this depends on the utilization of the particular network,
as well as on the quality of the NTP master. An NTP soft
ware package is included with the HBM software
catman®EASY.
Time format used
Based on 1.1.1990
Time stamp: 64‐bit
32‐bit seconds
32‐bit fractions of a second,
Resolution (1/232)
Further information about NTP can be found at
http://www.ntp.org
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