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Event Filter (S800 Filter)
The trigger bits words indicates which bits were set during the event. The encoding of the bits is the following:
In this section, the following diagram will be used to describe a 16-bit word sent by the Filter. The first row includes the value, either in decimal or hexadecimal format, or a descriptive note. The second row shows the value in binary (“X”s are used to describe arbitrary values that vary from event to event). The last row shows the bit number.
Time-stamp packet
The timestamp is coded by the XLMV72 time-stamp module for each event as a 64-bit word. The Event Filter parses it as a set of four consecutive 16-bit words.
5 |
0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 1 |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
0x5803 |
0 | 1 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
First 16-bits “chunk” of time-stamp |
X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Second 16-bits “chunk” of time-stamp |
X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Third 16-bits “chunk” of time-stamp |
X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Fourth 16-bits “chunk” of time-stamp |
X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Event-number packet
The event-number is given by the VMUSB scaler channels as a 48-bit word coded in two 32-bit words. The Event Filter parses it and re-formats it as a three 16-bit words.
4 |
0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
0x5804 |
0 | 1 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
First 16-bits “chunk” of event-number |
X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Second 16-bits “chunk” of event-number |
X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Third 16-bits “chunk” of event-number |
X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Trigger packet
The trigger packet includes a bit-pattern word (encoded by the ULM trigger module), with information about what sources triggered the event, and their corresponding time from the Phillips 7186 TDC.
from 2 to 7 |
0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
0x5801 |
0 | 1 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| Bit pattern |
0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | X | X | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
the encoding of the active bits is given by the following table:
Bit | Source |
0 | S800 (from E1 up) |
1 | Coincidence |
2 | External 1 |
3 | External 2 |
4 | Secondary (e.g. GRETINA) |
The time of each trigger source (except for “coincidences”) is given by a word that look like:
| Ch | time |
0 | 0 | 0 | X | X | X | X | X | X | X | X | X | X | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
there can be up to four time words (depending on whether time is greater than 0), one for each channel. The channel number Ch is given by:
Ch | Source |
8 | S800 (from E1 up) |
9 | External 1 |
10 | External 2 |
11 | Secondary (e.g. GRETINA) |
Time-of-flight packet
The time-of-flight packet includes all the timing values coded in the Phillips TDC and the XFP-FP and OBJ-FP ToF from the ORTEC TACs.
from 2 to 10 |
0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
0x5802 |
0 | 1 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
The time-of-flight information for each channel is coded in words that look like:
| Ch | time |
0 | 0 | 0 | X | X | X | X | X | X | X | X | X | X | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Up to eight of these words can be present (depending on wheter time is greater than 0): six from the Phillips TDC, and two from the XFP-FP and OBJ-FP TACs. The channel number Ch is given by:
Ch | Source |
6 | Phillips TDC time from the A1900 IM2 north scintillator (optional) |
7 | Phillips TDC time from the A1900 IM2 south scintillator (optional) |
12 | Phillips TDC time from the RF |
13 | Phillips TDC time from the OBJ scintillator |
14 | Phillips TDC time from the XFP scintillator |
15 | Phillips TDC time from the LaBr (optional) |
4 | XFP-FP time-of-flight from TAC |
5 | OBJ-FP time-of-flight from TAC |
Note that the time values from the Phillips TDC are subtracted by SpecTcl to the time from the S800 trigger E1 up (encoded in the trigger packet) in order to calculate the corresponding time-of-flight. On the other hand, the times from the TACs (Ch 4 and 5) correspond to actual time-of-flight values.
Scintillator packet
The scintillator packet includes the energy (from the FERA LeCroy module) and time (from the Phillips TDC) of the S800 FP scintillator signals. In the original configuration, there were 3 scintillators (E1, E2, and E3) which were later reduced to just one (E1) after the installation of the Hodoscope.
from 4 to 8 |
0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | X | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
0x5810 |
0 | 1 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
The energy (from the FERA module) and time (from the Phillips TDC) are given by two consecutive words:
| Ch | | energy |
0 | 0 | 0 | X | 0 | X | X | X | X | X | X | X | X | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| Ch | time |
0 | 0 | 0 | X | X | X | X | X | X | X | X | X | X | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
These words are sent by the Filter as long as energy is greater than 0 or Ch equals 2. The channel assignment given by the Filter is:
Channel | Source |
0 | E1 up |
1 | E1 down |
2 | Empty |
Ion-Chamber packet
The Ion-chamber packet includes the energies of the 16 “sub-chambers” registered by a Phillips 7164H ADC.
from 4 to 18 |
0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | X | X | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
0x5820 |
0 | 1 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
0x5821 |
0 | 1 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 1 |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
from 2 to 16 |
0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | X | X | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
The energy (from the Phillips 7164H ADC module) is given by a series of words that look like:
| Ch | energy |
0 | 0 | 0 | X | X | X | X | X | X | X | X | X | X | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Where Ch is the “sub-chamber” number (the ion-chamber is made out of 16 “sub-chambers”). The Filter gives an energy word for each “sub-chamber”, as long as energy is greater than 0.
|
X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|
| | | | | | | | | | | | | | | |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Bit |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |