10
TIME STAMPING
10
Time Stamping
The hardware and software allow you to use quTAU/quPSI devices to record time stamps
of registered events.
10.1
Writing and loading Time Stamps
The time stamps can be saved using different file formats:
10.1.1
Text File (ASCII)
The time stamps will be written into a text file. There will be two columns:
1. The time stamp in base units, i.e. roughly 81 ps.
2. The channel (1..8).
10.1.2
Binary File 10 Bytes per Event
In this case, the time stamp of each event is written to the file in binary mode. The
first 8 bytes correspond to the time stamp (in base units), while the following two bytes
correspond to the channel number (also in binary). Since the 64 bits of timing information
are more than are used internally, they will never overflow. (The internal time will overflow
after roughly 67
.
6 days, see Section
10.1.3
Binary File 5 bytes per Event
Similar to
, but with only 37 bits for the time stamp and 3 bits for the channel
information. This overflows a lot sooner (roughly after 11 seconds). If there is no event
for longer than 11 seconds, it will become impossible to reconstruct the time stamps
correctly.
10.1.4
Digital Signature for Offline Analysis
If this option is enabled, the written files will contain a digital signature such that, using
the supplied software, they can be read back in and analyzed offline, i.e. with the device
unplugged.
10.1.5
Loading Time Stamps
The saved File can later be read back in for further analysis.
quTAU/quPSI Manual V4.0 Page 25
