Contact

Dr. Roland Beyer
PostDoc / Beamline scientist
Nuclear Physics
roland.beyerAthzdr.de
Phone: +49 351 260 - 3281

Structure of the list-mode-data written by MBS

One List-Mode-Data readout event contains several trigger events. The number of these trigger events is adjustable by the v1495_trig_scal value of the V1495 FPGA Trigger Logic. Each trigger events consists of a number of 32 bit long data words. The type of word is identified by the 5 highest bit the so called GEO. Depending on this GEO the meaning of the different lower bits is shown in the list below.

The single Data words have the following bit-structure:

Time:

GEO = 0  
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 0 0 0 0 0/1 Time / 100 ms
Bit 26 is 0 for real time and 1 for live time
real and live time are written once only after the stop acquisition signal (trigger type 15) as an end of acquisition flag (this doesn't work in the multi branch setup because of a bug in MBS)

Time Flag:

GEO = 1  
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 0 0 0 1 Scaler Period / ms
the time flag is written as a header for the scaler data block and gives the time between each scaler readout

Scaler Values:

GEO = 2  
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 0 0 1 0 Channel Resol. R Counts ( right shifted by R bits)

Assignment of the scaler channels

Scaler ch

Content

0 FC OR
1 raw trigger = FC OR inhibited by veto
2 trigger = raw trigger with user defined length
3 downscaled trigger
4 LCLK = internal clock (40 MHz)
5 LCLK & veto
6 LCLK & !veto
7 N.C.
8 N.C.
9 N.C.
10 ADC words
11 QDC words
12 TDC words
13 TDC events
14 Veto words
15 LMD words
16 CFD FC1-1
17 CFD FC1-2
18 CFD FC1-3
19 CFD FC1-4
20 CFD FC1-5
21 CFD FC1-6
22 CFD FC1-7
23 CFD FC1-8
24 CFD FC PTB
25 accelerator
26 start of readout
27 N.C.
28 N.C.
29 N.C.
30 10 MHz-Pulser real
31 10 MHz-Pulser live

Veto Header:

GEO = 4  
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 0 1 0 0 N = number of Veto length values follwing
Subsequent to this single data word N further words are following. Each word contains only one 32 bit value. Note, that the order of the bytes of these words has to be swapped. The meaning of each value is the length in units of 25 ns of the following signals:

consecutive number

Signal

1 ADC Busy
2 QDC Busy
3 Total dead time
4 Trigger
5 Veto

ADC Header:

GEO = 5
            1                
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 0 1 0 1                       1 memorized
Ch. - 1
Event Counter

ADC Data:

GEO = 5                       0                              
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 0 1 0 1                       0 Channel Measurement

QDC Header:

GEO = 6 2  
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 0 1 1 0 0 1 0 Crate no.     memorized Ch.                

QDC Data:

GEO = 6 0  
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 0 1 1 0 0 0 0       Channel R       UN OV Measurement
R gives the range: 0 = low gain, 1 = high gain

TDC Data:

GEO = 7 1  
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 0 1 1 1 1 Channel Measurement

Assignment of TDC channels:

TDC Channel

Content

0 CFD FC1-1
1 CFD FC1-2
2 CFD FC1-3
3 CFD FC1-4
4 CFD FC1-5
5 CFD FC1-6
6 CFD FC1-7
7 CFD FC1-8
8 FC PTB
9 accelerator
10 trigger
11 veto start
12 veto end
13 TDC trigger
14 N.C.
15 N.C.

TDC Trailer:

GEO = 7 0  
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 0 1 1 1 0         Status       Word Counter

Trigger Time Tag:

GEO = 9  
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 1 0 0 1 Trigger Time / 800 ns

Contact

Dr. Roland Beyer
PostDoc / Beamline scientist
Nuclear Physics
roland.beyerAthzdr.de
Phone: +49 351 260 - 3281