EDOC302
EUROBALL DATA ACQUISITION SYSTEM
Group and Item Number Allocation
Edition 1.3 - Sept 23 1996
Edition 1.4 - Oct 12 1998
Edition 2.0 - Dec 7 1998
Edition 2.1 - Mar 24 1999
Nuclear Physics Support Group
Central Laboratory of the Research Councils
Daresbury Laboratory
Group and Item Number Allocation for Euroball
This document defines the allocation of group and item numbers used by the Euroball VXI electronics. For a description of the raw data format which uses these numbers see the document edoc300.
Group number allocation for Euroball
The allocation of groups for Euroball is an extension of that used for Eurogam.
detector type | group numbers |
---|---|
ReadOut Controllers (STR 8080) | 248 - 255 |
Master Trigger | 247 |
BGO Inner Ball (Eurogam IV) (raw data) | 81 - 99 |
BGO Inner Ball (Eurogam IV) (sum) | 100 |
Tapered (Eurogam I) | 51 - 80 |
Clover (Eurogam II) | 21 - 50 |
Cluster (Euroball III) | 1 - 20 |
Note - Eurogam uses group 255 (only) for all readout controllers and for the
master trigger module.
The group number space between 101 and 240 is available for use by
readout systems for ancillary detectors within Euroball.
Item number allocation for the Eurogam Master Trigger VXI card.
The Eurogam Master Trigger card generates the following data items.
data item | item number |
---|---|
event type | 0 |
Raw Ge Sumbus | 1 |
Clean Ge Sumbus | 2 |
BGO Sumbus | 3 |
User Sumbus | 4 |
Timing (TAC) | 5 |
Item number allocation for the Euroball Master Trigger VXI card.
The Euroball Master Trigger card generates the following data items.
data item | item number |
---|---|
Sumbus 1 Multiplicity | 0 |
Sumbus 2 Multiplicity | 1 |
Sumbus 3 Multiplicity | 2 |
Sumbus 4 Multiplicity | 3 |
TAC | 4 |
Pattern/trigger type | 5 |
Event Number LSB | 6 |
Event Number MSB | 7 |
Item number allocation for the Euroball Ge/BGO VXI cards.
The Ge card provides 6 electronics channels each of which instrument one Euroball Ge tapered detector. Each channel has 4 ADCs.
ADC | item number |
---|---|
20Mev | 0 |
4Mev | 1 |
Timing (FT) | 2 |
Timing (CO) | 3 |
The BGO card provides 6 electronics channels each of which instrument one BGO shield for a Euroball Ge tapered detector. Each channel has 3 ADCs.
ADC | item number |
---|---|
total energy (Energy) | 4 |
timing (TAC) | 5 |
hit pattern (Pattern) | 6 |
Item number allocation for the Euroball Clover VXI card.
The Clover card instruments the 4 element Euroball Ge Clover detector and its associated BGO shield. For the purposes of this note the Ge elements will be labelled as Ge-element# which takes the values 1 => 4. Each element has 4 ADCs which will be labelled as adc# which takes the values 0 => 3.
ADC | adc# |
---|---|
20Mev | 0 |
4Mev | 1 |
Timing (FT) | 2 |
Timing (CO) | 3 |
The item number is given by
The Euroball data acquisition control system identifies the elements as GeA
to GeD where A is element number 1 and D is element number 4. Thus
GeA.20Mev is item 8 GeA.4Mev is item 9 through to GeD.CO which is item 23
The Ge electronics includes one spare element which can be switched in to replace any one of the normal 4 elements in the event of a failure. This spare element will be assigned the item numbers allocated to the element it has replaced.
The Clover BGO electronics instruments the Clover detector BGO shield and provides 3 sum data items.
data item | item number |
---|---|
total energy (Energy) | 4 |
timing (TAC) | 5 |
hit pattern (Pattern) | 6 |
Item number allocation for the Euroball Cluster VXI card.
The Cluster Ge card instruments the 7 element Euroball Ge Cluster detector. For the purposes of this note the elements will be labelled as Ge-element# which takes the values 1 => 7. Each element has 3 ADCs which will be labelled as adc# which takes the values 0 => 2.
ADC | adc# |
---|---|
20Mev | 0 |
4Mev | 1 |
Timing (FT) | 2 |
The item number is given by
The Euroball data acquisition control system identifies the elements as GeA to GeG where A is element number 1 and G is element number 7. Thus
GeA.20Mev is item 0 GeA.4Mev is item 1 through to GeG.FT which is item 20
The Cluster BGO card instruments the 18 element Euroball BGO shield and back-catcher. For the purposes of this note the elements will be labelled as BGO-element# which takes the values 1 => 18. Each element has 2 ADCs which will be labelled as adc# which takes the values 0 => 1. Additionally the BGO electronics provides 3 sum data items.
data item | item number | |
---|---|---|
sum | BGOSum.Energy | 21 |
sum | BGOSum.TAC | 22 |
hit pattern | BGOPattern.High | 23 |
hit pattern | BGOPattern.Low | 24 |
and
ADC | adc# |
---|---|
Energy | 0 |
Timing | 1 |
The item number is given by
The Euroball data acquisition control system identifies the elements as BGOA to BGOR where A is element number 1 and R is element number 18. Thus
BGOA.Energy is item 25 BGOA.TAC is item 26 through to BGOR.TAC which is item 60
Both the Ge and BGO electronics include one spare element which can be switched in to replace any one of the normal 7 or 18 elements in the event of a failure. This spare element will be assigned the item numbers allocated to the element it has replaced.
Item number allocation for the Euroball IV BGO Inner Ball VXI cards.
The BGO VXI card provides 6 electronics channels each of which can instrument 10 BGO Inner Ball segments. Each channel has 3 ADCs.
ADC | item number |
---|---|
total energy (Energy) | 0 |
hit pattern (Pattern) | 1 |
timing (TAC) | 2 |
The total energy data item will be the sum energy of the group of 10 bgo segments connected to that input and the hit pattern will have a bit set for each segment which has fired and thus can give the multiplicity for the group of segments.
A Sum group will be generated in software by summing all the partial energies and calculating a total BGO multiplicity.
item | item number |
---|---|
total energy (Energy) | 0 |
multiplicity (Mult) | 1 |
Item number allocation for the GIR.
item | item # |
---|---|
error report | 63 |
event number (EvNum) | 62 (61 - see note) |
All VXI cards which use the GIR for VXI interfacing have a number of
common data item generated within the GIR.
The error report item is used by the GIR to report various internally detected
errors. The error cause is reported as a code in the data part of the 32 bit
data word.
The event number item is the reconstructed event number generated by the
GIR using the algorithm defined in the document EDOC301.
Note - In the case of the Cluster electronics which is in fact 2 VXI cards the Ge card GIR is allocated item number 62 and the BGO card GIR is allocated item number 61.
Group and Item allocation for the ReadOut Controllers (VRE).
The ReadOut Controllers use groups 248 - 255. Each group corresponds to a physical DT32 readout bus and can accomodate 15 ReadOut Controllers. For VRE module n (i.e. VREn) the group number used is given by 248 + (n/16). Hence the first DT32 bus (with n=0) has VRE modules VRE1 => VRE15; and the second DT32 bus (with n=1) has VRE modules VRE17 => VRE31 etc.
For a specific DT32 bus each VRE has a number i given by n modulo 16 or n - ( (n/16) * 16). The first VRE on the DT32 bus has i=1 and the last has i=15. If there is only one VRE on the DT32 bus then it has i=15. For further details see the document EDOC300.
The use of item numbers by the ReadOut Controllers is thus
data item | item number | item number range |
---|---|---|
start sub event token | i | 1 - 15 |
event number LSW | i + 16 | 17 - 31 |
event number MSW | i + 32 | 33 - 47 |
end sub event token | i + 48 | 49 - 63 |
No VRE uses the value i=0 and hence the items 0,16,32 & 48 are not allocated.