Nomenclature Conventions

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Detector Orientation and terminology

The following diagram shows the terminology used in the current DAQ

Edet terminology.JPG

Conventions followed in the Firmware

All physical entities are numbered from 1(not from 0), though in software, all counts start from 0.

chc: Compton Hall C
s1: slave 1 v1495
s2: slave 2 v1495
s3: slave 3 v1495

The diamond based electron detector setup uses 4 planes of the detector. The detector plane on the upstream side is termed 'plane 1' and the plane counts up, with the last plane termed plane 4.

Each detector has a total of 96 strips, which are being processed in groups of 32 strips each, termed as the top, middle and bottom groups of 32 strips go to s1, s2 and s3 respectively.

Among the strips of the detector, the strip which is closest to the main beam is termed 'strip 1' and is counted upwards.

In the electron detector Flags file, for setting the appropriate mask values, you would need to know:

p1t : plane 1, top 32 strips    ; the top-most strip is the strip closet to the beam (going to A-port, slave 1)
p1m : plane 1, middle 32 strips (going to A-port, slave 2)
p1b : plane 1, bottom 32 strips ; the bottom-most strip is that which will be farthest from beam (going to A-port, slave 3)
p2t : plane 2, top 32 strips    (going to B-port, slave 1)
p2m : plane 2, middle 32 strips (going to B-port, slave 2)
p2b : plane 2, bottom 32 strips (going to B-port, slave 3)
p3t : plane 3, top 32 strips    (going to D-port, slave 1)
p3m : plane 3, middle 32 strips (going to D-port, slave 2)
p3b : plane 3, bottom 32 strips (going to D-port, slave 3)
p4t : plane 4, top 32 strips    (going to E-port, slave 1)
p4m : plane 4, middle 32 strips (going to E-port, slave 2)
p4b : plane 4, bottom 32 strips (going to E-port, slave 3)

a value of '1' enables the strip, '0' disables it. The mask values are set in groups of 32, it can be entered in either hex or integer value (but not binary) example:

 If strip 1 is to be masked off on plane 1, 
 strip 24 is to be masked off on plane 2
 strip 47 is to be masked off on plane 3
 all strips on plane 4 to be left active
 leaving all other strips active on all planes; then we have to put: 

 p1b = 0xfffffffe, p1m = 0xffffffff, p1t = 0xffffffff
 p2b = 0xfff7ffff, p2m = 0xffffffff, p2t = 0xffffffff
 p3b = 0xffffffff, p3m = 0xffffbfff, p3t = 0xffffffff

cluster: a group of 8 strips being ORed together to get a trigger decision. 

The following short-hands have been used very often in parameters/variable names that a User may deal with.

PW: Pulse Width          Rd: read
TL: Trigger Logic        Wr: Write
DL: Delay Line           clk: clock
HO: HoldOff              DIN: Data Input
GE: Good Event           Buf: Buffer
MB: Master Board         Stat: statistics