Comprehensive Manual94
© 2018 Nortek AS
4.3 Synchronizing with Other Instruments
It is possible to synchronize instruments together, or its sampling can be controlled by other
sensors. This comes in handy if there is a need to use several instruments for a single set of
measurements.
4.3.1 Vector
Sync out (Vector acts as Master)
The Vector can be synchronized with other instruments via the SyncIn and SyncOut. The
synchronization option requires that the correct wiring harness is installed in your system. The
SyncOut signal consists of 1.95 ms long, 3.3V pulses that can be configured for two different
schemes of output synchronization. The selection of the type of SyncOut signal is made on the
Advanced tab in deployment planning:
If Output Sync for other sensor is selected, the SyncOut pulse will be output in the middle of each
velocity-sampling interval.
If Output Sync for Vector is used, the SyncOut pulse will be output at the completion of each
sampling interval.
In addition, one SyncOut pulse will be output when the sampling of velocities is started.
Figure: Sampling Interval
Sync In (Vector acts as Slave)
The SyncIn signal permits external control of the sampling. There are three possible modes of
operation that can be set for Input Sync:
No Sync. In this mode, the Vector ignores the SyncIn signal and data collection starts under
software control only.
Start on Sync. In this mode, the Vector starts data collection on the rising edge of the SyncIn
signal. Sampling of velocities then proceeds at the set sampling rate. After data collection is
started the SyncIn is ignored.
Sample on Sync. In this mode, the Vector outputs a sample after every rising edge of SyncIn. To
use this mode, the Start on Sync mode must be used as well. Therefore, the first rising edge
starts the averaging process for the first sample only. The first data sample is output on the
second rising edge of SyncIn. The output data at each rising edge of SyncIn will correspond to an
average since the previouis rising edge of the SyncIn. The Vector must be configured with the
setup software for a sampling rate that is equal to or higher than the sampling rate that will be
used.
Example: If the signal on the SyncIn input to the Vector is generated to correspond to a sampling
rate of 25 Hz, the Vector should be configured in software for a sampling rate of 32 Hz. In most
cases, it will be sufficient to synchronize different Vectors using Start on Sync.
Instruments shipped after November 2000 are fitted with a real time clock with an accuracy of ±1
min/year over a temperature range of 0–40 °C. Over a burst period of for example 1 hour, the
maximum clock drift between two Vectors will then be 13.7 ms. Since they will operate at the same
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