Media: copper, LVDS-28 bit
Record Length: fixed, 7 frames

TS\Bit	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
1	BOR			HP	PM		Octant			SCL	FX	SCT					RelSector				Data Type					Rec Type
2				HP	SC1								XPT+TC			XPT-TC					XPT+NC			XPT-NC
3				HP	SC2								HPT+TC			HPT-TC					HPT+NC			HPT-NC
4				HP	SC3								MPT+TC			MPT-TC					MPT+NC			MPT-NC			#PSC
5				HP	SC4								LPT+TC			LPT-TC					LPT+NC			LPT-NC
6				HP	SUM of PT								Occupancy								Isolated Track
7					Vertical Parity

Field Definitions

BOR       = beginning of record, "111"

HP        = Horizontal Parity bit

PM        = Pass-and-Mark, not supported, "00"

Octant    = The octant number, range 0-7

SCL       = SCLinit control bit

FX        = First Crossing control bit marks bunch crossing number 7

SCT       = Singlet Count Type. If this bit is set the four singlet counts are grouped
            by layer type.  Otherwise, the singlet counts are azimuthally divided into
            four quarter-sector groups.  See below...

RelSector = the relative address of the sector within the octant, range 0-9

Data Type = L1CFT, "00101"

Rec Type  = L1 record, "111"

XPT+TC    = Track counts sorted by:
             PT (XPT=max, HPT=high, MPT=medium, LPT=low)
             Curvature (+ or -)
             CPS cluster association (T=tight match, N=no match)

#PSC      = The number of CPS clusters found in this sector ("11" means 3 or more)

Sum of PT = The total sum of transverse momentum for all tracks found in this sector

Occupancy = The number of doublet fibers hit, range 0-240

SC*       = The total number of singlet fibers hit, arranged in four groups.
            Singlets are grouped in one of two ways, depending on the SCT bit:

                 SCT = 1 (singlet counts grouped by layer)
                  SC1 = singlet count for layers ai, ao, bi, bo 
                  SC2 = singlet count for layers ci, co, di, do 
                  SC3 = singlet count for layers ei, eo, fi, fo 
                  SC4 = singlet count for layers gi, go, hi, ho 

                 SCT = 0 (singlet counts grouped by azimuthally divided quarter-sector)
                  SC1 = singlet count for quarter sector    phi increasing
                  SC2 = singlet count for quarter sector          &darr
                  SC3 = singlet count for quarter sector          &darr
                  SC4 = singlet count for quarter sector          &darr

Isolated Track = If only one track is found in this sector and no tracks
                 are found either of the adjacent sectors this byte will
                 be filled in as follows:

                   bit 7:     Set to indicate a valid isolated track byte.
                              If this bit is cleared ignore the rest of the byte.
                   bits[6:4]: CPS cluster association "001" = tight match, "000" = no match
                   bit 3:     Track curvature bit
                   bits[2:1]: Track PT bin ("00" = Max, "01" = High, "10" = Medium, "11" = Low)
                   bit 0:     Set to indicate that the sector doublet occupancy is below
                              given threshold, currently ~6%

Revision History

01 Nov 2005 : created JTO
03 Jan 2006 : parity links
23 Mar 2006 : change to DFEA2
15 Sep 2006 : add singlet count field
22 Sep 2006 : changed singlet count to four fields AB CD EF GH
06 Dec 2006 : added SCT indicator bit to frame one and switch to
              more general SC1..SC4 fields for the singlet counts.