HBM FS22 SI User Manual page 27

Number of devices
to be synchronized
Synchronization
accuracy
Synchronization
settling time
Synchronization
master
FS22 SI
Synchronization is again of extreme importance in such
systems. When an NTP server is running the Interrogator
will start synching as soon as a first communication from
the server is received.
For details on the other equipment please refer to their
respective user manuals.
Synchronization process
Each interrogator synchronizes its internal clock with the
NTP server. Upon starting, all devices and the NTP
server need some settling time to achieve the best syn­
chronism possible.
The following features for NTP synchronization are avail­
able:
Unlimited
10 μs to 10 ms
Up to 30 min during first start, up to 2 min during restart
External SyncMaster, e.g. PC
For a good synchronization, the dedicated NTP server
should run continuously. The accuracy is described by
the two values:
S Offset: average deviation from time server
S Jitter: typical variation range of the offset value
The clock synchronization is classified using the following
offset intervals:
S <500 μs: excellent
S <1 ms: very good
A4249-8.0 HBM: public
Operation
27