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SensL © 2011
15
USER MANUAL
HRM-TDC
SensL © 2011
15
> Hrm-tdc System Description > Histogram – Multi-stop (“multiscaler/counter”)
HISTOGRAM – MULTI-STOP (“MULTISCALER/COUNTER”)
Figure 6
In this mode, multiple STOP events following a single START event are recorded and their corresponding time bins in
the histogram incremented (Fig.6a). The following START input will reset the timer and the following STOP events will
be again recorded until another START is received. The process is illustrated in Fig.6b and Fig.6c. This is repeated to
build up a histogram in memory. Data is saved in .CSV format. The GUI will display a plot similar to that in Fig.5d. This
mode is also referred to as “
Multiscaler/Counter”
in the SIE. Please note that FIFO is not employed in this mode.
The Td (dead time) parameter is applicable in histogram multi-stop mode and limits the maximum frequency
achievable. Tm is the minimum time between any start and a subsequent stop.
Note:
In this mode the START signal is a low frequency clock (less than 7 MHz). The STOP signals will be the events.
Unlike the single-stop mode, the 27ps timing module is not reset after the first event. Due to the long clock period it
will be possible for the same channel to receive a number of events per clock cycle. Hence, in this mode the time-
bins will fill up to plot the occurrence of events over the period of the clock cycle. Each new START signal will reset
the 27ps timing module. This allows the system to build up a plot of all the events within the START pulse cycle.
Once again the flexibility of the Address Routing Register provides a wide range of options from single to multiple
curves.
Min Time Bin Size:
27ps
Max Time Bin Size:
143
m
s
Max No. Time Bins:
4,194,304
Time Bin Depth:
65,536 or 4,294,967,296
Max Count Rate:
4.5Mcps
Max Image Size:
2048 x 4096
a)
b)
c)
Fig.2b