FAST ComTec MCA4A, User Manual

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Software Description
4.2 File formats
The .mpa format is used to save all spectra in a single file. It starts with an ASCII header containing the
settings and then the spectra follow one after the other, each proceeded with a header line like
[DATA0,16384 ]
(This means the first single spectrum with a length of 16384 channels.)
[DATA1,16384 ]
(This means the second single spectra...)
[CDAT0,16384]
(This is the first dual parameter or calculated spectra with a length of 16384 channels. The enumeration
starts again at zero after all "physical" spectra.)
The format of the data itself can be ASCII, Binary, GANAAS, EMSA or CSV (see below). Individual spectra
can also be saved into single files. If "separate header" is checked in the data operations dialog, such
spectra data is written into two separate files, one with extension .mp containing configuration data and one
containing pure spectra data with an extension indicating the chosen format. The .mp file contains the
settings in ASCII format using the control language described in section 4.3
Spectra data files with extension .asc contain in each line one decimal number in ASCII containing the
corresponding count value in the histogram.
Binary data files with extension .dat are written with 4 bytes per data value, as usual in the Intel world in
reverse order i.e. the least significant byte comes first.
GANAAS data files with extension .spe contain 10 data in ASCII format after a simple header. This format is
used by the IAEA gamma spectra evaluation program GANAAS.
EMSA data files are in ASCII with extension .emsa and follow the NIST EMSA spectrum file format.
Another ASCII file format is the x y format with extension .csv. It can be read for example with Excel and
contains the channel number and content as two decimal numbers in ASCII per line separated by a TAB
character.
List files have the extension .lst and start with a header containing the usual report and configuration data in
ASCII as in the .mpa or .mp files. The header ends with a line containing [DATA].
Then follows the data, depending on the format chosen for the data file either in ASCII or binary. In ASCII
format one data word is written in hex format per line. In binary format each stop event is written with 8 bytes,
as usual in the Intel world in the reverse order, i.e. the least significant byte comes first. A single event is a 64
bit number (8 bytes), or in scope mode a multiple of such 8 byte numbers.
The lowest two bits 0 and 1 are the channel number 0..3 for ADC1..ADC4.
Bit 2 is a flag for pileup detected.
Bit 3 indicates scope mode. If it is on, more data words follow.
Bit 4 – 47 is a 44 bit event time. If the RTC option is enabled, it is in units of 8 ns, otherwise in units of 1
msec. With tag bits enabled, the 8 most significant event time bits are used for tagging and represent the 8
dig I/O input bits. If pulse width measurement is enabled, the most significant 12 bits are used for the pulse
width and represent the pulse width at the threshold level in units of 64 ns.
Bit 48 – 63 are the 16 bit ADC value or in scope mode the length of the waveform data minus one in units of
16 bit words. This size value can be 4095, 8191, 16383 or 32767. The waveform data follow then next.
Here is an example of list file data:
[DATA]
adf20000000266f0
ad4f0000000266f2
ae0c0000000266f3
ae820000000266f1
ae850000000573a1
ad500000000573b2
ae0e0000000573a3
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