Media: copper, LVDS-28 bit
Record Length: variable, depends on the number of reported clusters

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
BOR			HP	PM				N	#OBJ VP			#OBJ						#OBJ HP		Data Type					Rec Type
			HP	Turn																Tick
			HP	Cluster Object(s)
				Vertical Parity

Field Definitions

note: empty cells or cells marked 'reserved' will contain zeros

BOR = beginning of record, "111"

HP = Horizontal Parity bit

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

N = Set to indicate the North end cap

#OBJ VP = Vertical Parity bits for the #OBJ field

#OBJ = The number of Cluster Objects contained in this record, range 0-24. Currently forced to ZERO!

#OBJ HP = Horizontal Parity bits for the #OBJ field

Data Type = L2FPS, "00010"

Rec Type = L2 record, "000"

Turn = The accelerator turn (revolution) number

Tick = The accelerator bunch crossing number

Cluster Object = The U and V layer cluster lists are each truncated at 12 clusters.
The cluster lists are concatenated with no gaps in between and U layer clusters are listed
first in order of increasing eta. Each Cluster Object is 24 bits, defined as:

• bits [23:16]: The cluster center position, range 1-144
• bits [15:13]: Cluster width ("111" = means 7 strips wide or wider)
• bit 15: Layer identifier: 0 = V, 1 = U
• bits [11:8]: Wedge number, range 0-15 (see the header for the North/South bit)
• bit 7: Set to indicate MIP association
• bits [6:0]: MIP bitmap. If bit 7 is set this field will contain the 7 MIP strips nearest to the cluster center.

Revision History

01 Nov 2005: created JTO
17 Jan 2006: added parity links
18 Jul 2006: add note about number of objects == 0.